024

S

CE 017 426

TITLE Investigating Accidents in the Workplace. A Mammalfor Complian Safety and Realth Officere.

INSTITUTION Occupation Safety .and Health.Administration,Washington, D.C..-

REPORT NO, OSHA-2288 .40

POE DATE 77NOTE 20p.

RDJS PRICE d ? -$Q.83 RC -$1.67 Plus Postage.DESCRIPTORS Accident Prevention; *Accidents; Data AnalysiskData

Collection; Environmental Influences; FederalRegulation; Field Check; Field Interviews; Guides;*Inspection; Manuals; Safety; *Work Environment

IDERTI *Compliance Safety and Health Officers; UnitedStates

ABSTRACTThis manual_was developed for Compliance. Safety and

Health Officers (CSHO) of the Occupational Safety and HealthAdministration (OSHA) to help then carry out their responsibilitieswhen investigating workplace accidents. The content is presented infour sections. The first overviews the investigative roles of CSHOofficers,-including nreinvestigation, onsite, andYcourtroomactivities. Section 2 on investigative techniques discussesdocumentation, interviewing, and accident scene examination. The nextsection covers causal jactors analysis and reporting, while the lastone summarizes the manual. (EM)

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* Reproductions supplied by EDPS are the best that can be madefrom the original document.

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_§ Adthe Woik

plianceOfficers

ace

U.S. Department of lobarRay Marshall, Secretary,

Occupational Safety andHealth AdministrationELM Bingham, Assistant Secretary1977

OSHA 2288

s OE PAITirINTLIF meAL TM.EPOCATIOPI WELFARE

TtaPo*k INSTITUTE, OrEptjc*TION

t BEENE Ac *ECU ivtp AI )M

--c NIZATioNtORiGiN-OR OFUNiONS

*!_if 0 DO A.1). NICESSARILY BENE t4A7,0AIAL INS/ ITU tBEDuc* y 10*1 pOsi tOft 00 POLICY

CONTENT

AN OVERVIEW TO YOUR ROLE A$ ANINVESTIGATOR

A PreinVestigatIon Activity

B. Ortsite Activity

Page:

"3

4

1. Inv,estigative Factions 4

2. Inspections While On Site 4

3. Disclosure of Information DuringInvestigation 4

4. Your Relationship to Other Investigators 5

C. The Courtroom Efer,spective

INVESTIOATIVE TECHNIQUES .. ...... . .. 7

A. Site DOcumenfation 7

1. Photographing' 7

2. Sktiching or Drawing 8

B. Interviewing

1. Guidelines for Conducting InvestigativeIntervievis

2. Determining Whom to Interuiew

3 Conducting a Comprehensive Interview 9

4 Credibility of Witnesses 9

5 Preparing Statements 10

6 Analyzing the Testimony '10

C. Accident Scene Examination 10

1 Sampling 10'

2. Laboratory Analysis 10

D Other Considerations

1 Weather

2 Fire

3 Fatalities

4 Records

10

10

141

11

CONTENTS trontinued) .

Page

III. ANALYSIS AND REPORTING 13

A. Causal actors Analysis ... . ... . . 13

1. Anal al ,Techniques 13

2. Three ypee of Giulio* 13

3. Sources of Failure 14

B. Reports Preparation I .. ... . . 1 s

IV. SUMMARY . . ........... . ... 16

The Occupational Safety and Health Administration has theauthority to investigate workplace, accidents for the purpose de-termining( I) if there has been a violatioh of Federalsafety and h thstandard's. (2) whether any such standards require revision, (3)whether any new standards need to be developed, and (4) if coffee-tiveaction will prevent recurrence in the future. To warrant investi-gation, accidents should meet one or rnore of the following criteria:

One or more fatalities, five or more employees hospitalized, or

any combination thereof

Frequently occurring incidents of like nature

Accidents or events of national importance that involved exten-sive property damage and could have caused death or multipleinjuries

Those occurring_ in industries that are the subject of any special

program

Those involving significant publicity

As a compliance officer, your concern is with conditions of theworkplace at the time of your inspection. With properly specifiedstandards. your job becomes a straightforward one of assessingwhether or not the jobsite is in compliance. As an investigator. how-ever, your mission is to reconstruct the conditions and events of theworkplace at the time of an accident. Unlike compliance.inspection. it

is not alwovelear what you should a looking for (as explanationsfor causes of an accident) or when your job has been completed( through haying identified all causes of the accident under investiga-

tion).'his fundamental difference between investigation and inspection

will require you to use a broader range of techniques for gathering in-

(urination and to develop new analytical skills for finding the cause ofaccidents. Recogniiing that your role as a CSHO is primarily one ofcompliance inspection, this manual has been developed to aid you in

carrying out your responsibilities as an accident investigator.I his manual is not a policy-setting document or a procedures

manual. On issues that relate to formal conduct and procedures. you

are relerred to the field Operation8 Manual and to the current rele-

. ant official directives and memoranda.lours to he completed during investigation are not n-

eluded in this manual. since they are subject to change.Material contained in this publication is in the public don and

he reproduced. I ulh, or partially, without permission of the

I edei (ioi.eilifient. Source credit is requestedbut not req ired

tam u. anon., culuirracre, run Pika.autr1 litt*I I 7/MUMCREDENTIALS 0 CSHO-Identifitadon Card

PAPERS, 0 OSHA StandardsIt 0 OSHA Ric OSHA Form previous

DOCUMENTS 0 Area Rom] Map

SAFETYEOUIPMENT

0, Hard HatO Safety glasses or Goggle,0 EarPluilsO Safety Shoes/Rubber BootsO Protective Clothing

CameraFilmBlack and White

Colora

PHOTOGRAPHY 0 Flash and Other AttachmentsO Photography Log

Sealing novicesO Folding Rule (in fractions o

SKETCHING

O Graph PaperO Ruler, Protractor, CompassO PencilsO Carbon Paper

INTERVIEWING Interview Comment Sheet

SAMPLING

WRECKAGEEXAMINATION

OTHER

O Sample LogChemical/Reflective Detectors (Gases)

O Containers and Caps (Liquids)Iml Plastic Sags and Envelopes (Solids)

Tags/Labels

Parts Retrieval Log

Stop WatchMagnifying GlassSticks of ChalkCompass50-Foot Cloth Tape

1)

I. AN OVERVIEW TO YOUR ROLE AS AN INVESTIGATOR

Accident investigation, like crime detection and medi-cal diagnosis, often entails a microscopic search forunknown,. Every factor relating to an incident must bediscovered, evaluated, and analyzed, in order to detersmine the actual sequence of events and causes of theaccident. The work must be thorough, Often it is a d if

ficult assignment,' but its successful accomplishmentwill make an important contribution to preventingfuture accidents. All too often, accidents that are ulti-mately attributable to the same set of causes have

repeatedly occurred because investigators lacked thezeal, ability, or knowledge to obtain and analyze all the

facts.Throughout your investigation, interviews, and

report writing. you shoulrrrrerrrher that rythingyou do has two goats:

I. Determine the cause of the accident

2. Prevent it from hap ening again

Certain principles of accident investigation should hefollowed if maximum results arc to he secured:

The investigator(%) should he equal', to the

demands of the investigation to he undertaken.You should have basic familiarity µ ith the equip-ment. operation, or process involved and anunderstanding of the conditions or situations thatare likely to bring about accidents of the type that

you are to investigate

The investigation work force should be adequate

to meet the loci of effort required I he sire of theinvestigation team can vacs %,k idel% , depending

upon the nature of the accident, its magnitude.and its technical complooty.

(letting to the scene of an accident prompt's is

extremely important. In all (W10, after the

accident has happened and time passes hs, rt

Mies more difficult to obtain fact, accuratekndifions change quickly in mans Is pes of acci-

dents, such as those my 01% ing, esposions or fire

Prompt iii esogation unpro% es the likelihoodthat the accident on't reoccur due the same

tanks procedure, or ers ironmental condition,

I wo of the most important attribute, sou shinilddes clop are comprehen,a% enc., and creams itNothing can replace a thor ough ioh of gather ingfacts through photograpto., inters lev.ing. ace -dent reconst [whirl, etc '%riah.so, (it the 01. IdcoLc

(both during and after it, %.ollectiont depend,he:oil% upon sour erean it% %,Iiiiethit4! s,haeh

can &Achy only with espeoence

Accidents arc carets mined hs ,inglc hiit,rr. butrather hs the coincidence of Nes et AI ionalitnurevents

cr

The real purpose of accident investigation is togather information which can lead to improvedsafety and health conditions in the work environ-ment, Your work, therefore, is not complete mailyou have determined whether a violation ofFederal safety and health standards could havecontributed or did contribute to the accident,whether enforcement of those standards couldhave prevented the accident, and whether OSHAstandards should be revised to cover any hazard-ous condition contributing to the accident. Whileit is not your job as a CSHO to make speCific re-

commendations for corrective.action, your find-ings on ishe cause of the accident are an essentialfirst step toward correcting hazardous situations.

A. Preinvestigation Activity

(.once you are assigned to investigate an accident, oneof the first things yo should do is review any existingtile on that employer. Your attention should befocused on three steps: ( I) review the OSHA-36 Form,if one has been prepared and filed; (-2) see what theaccident history of the company has been; and. (3)

review the file for any activity relating tp standards,inspection reports, citations, employee complaints,etc. All of this information will help you to determinewhether or not you will need special equipmentir sup-

porting technical specialists.(jive careful consideration to the equipment to be

used in the investigation. Although much of the equip-

ment is standard for most investigations, carefulthought should he given to the types of special equip-ment that might he needed. In Figure . a checklist is

provided for basic equipment Note that this list hasbeen restricted to the most common equipment.

Regarding safety equipment, you should he pre -

pared' to comply with :ill employer safety and healthrules and practices at the site of the accident. by wear-

ing or using required safety clothing or equipment.Bear in mind that an accident can greatly change the

characteristics of a work area, creating the need for dif-

ferent or specialized safety. equipment, jF

Although ou µill report ro the accident scenepronrptls. sou Ma he confronted with a situationwhew the new, media hae covered the incident even

helot c s ou -were assigned to the case. Occasionally you

may find t heir photographic or film cmerage aluahleit the ...ecno has been altered het y4een the occurrence ofInc accident and ottr arm al. In general, how eer, it is

heifer to refs on information and photographs sou oh-

fain -ourself fin collecting evidence and making;coot RelY on information go, en hs the news medta

Inl 01 10%t resort

Omits Activity 1%

1. INVESTIGATIVE 'FUNCTI bN

Every accident is unique and requires an investigationtailored to the particular situation. There are, of.course, certain techniques that should be employed inconducting the data gathering analysis. The actualsequence and amounts of investigative activities varywith each invatilgation (the one exception being thatyou must seek out the employer or his representtiveImmediately upon arrival and present yourdentia -). By way of introduction to your role as an in.-vestip -r, several steps in the field portion oT the in--vestigat'o process tem briefly described below.

Opening ConferenceThere must be an openingconference with the employer or the employer's rep-resentative, The conference is very important to theoverall success of the investigation, since thecooperation of employer and employees will greatlyfacilitate obtaining accurate evidence. This initialmeeting will set the tone for your relationship withe.

. the employer throughout the investigation. If theaccident happened recently, you will want to makethis session brief, so that you can begin your investi-gation,

Walkaround -*As soon as is reasonable, you shoulduct a walkaround, accorppanied by employer

ployee representatives. In cases where there isthorized employee representative, you shouldIt with an appropriate number of employees

ng the walkaround.

Administrative Details --You may wish, if possiblel,to arrange for office and storage space. If an officecan be made available to you, yoU will find it a con-venient place to make telephone calls, store yourrecords and equipment, interview witnesses, anti-conduct onsite analyses. An area large enough tostore debris and wreckage in cases of fire or explo-sion wall also be useful. The lack of these facilities,however, will not seriously hamper your work. Theyare desirable but by no means necessary.

In conducting your investigation. you will morethan likely need some assistance on technicalmatters. Employees at the w orkplace can hevaluable in this area. as they are intimately familiarwith the accident _scene's rnachiners, buildingstructure, piping. wiring, etc.

Documenting the scene An immediate task will beto record the scene of the accident, as it exists atterthe accident !he area should he restricted toawl-lowed petsons iesen it only for a very braetime). Nei soueshould take sour photographs andmake sketches from ,several angles Later, oushould gather other int ormanon about nurmal con-(hubris, such as maps, floor plans, clesiwons ofbuildings. descriptions and locations ofequipment that has heen roused or dainaged,

Preserving Pvidence In rnarr. instances, condo]lions change rapidly. and it-rote-ohne after an acct-

4

dent, due to such things as weather conditions or theneed to make the area suitable for working again. If ryou moat quickly, the accident scene may f beblocked off from unauthorized persons or thedence may be moved into a secure storage yea if oneis available.

InterviewingIrensany accident investigations, thebulk of evidence on the sequence of events.leadiup tO-the accident 4,01:Kilned through interviewIf you arrive at the scene soon after theaccident hataken place, you should at least conduct brief interviews with workers and other witnesses to obtain aninitial idea of what happened and to record the phy-sical and emotional conditions of thole involvedwith the accident. You should conduct de-tailed interviews later.

Closing ConferenceWhen you have completedyour onsite work, you must conduct a closing eon-ference with the employer and advise and discusswith that employer any apparent violations dis-covered during the walkaround and investigation.Since much additional analysis work concerning theaccident may be required, you should avoid discuss-ing specific findings of your investigation. You maytell the employer of the analysis and report prepara-tion procedure, and you may make some interimsuggestions to assure a safe work environment whilethe analysis and final reports are being prepared.

2. INSPECTION WHILE ON SITE

As a CSI-10, you should be prepared to onduct aninspection of the workplace in addition to the accidentinvestigation. The Area Director will make the deter-mination, depending on the circumstances surround-ing the accident, resources available, and other priorityrequirements. The inspection may be conducted be-fore, concurrent with, or after the investigation. If, inthe course of the investigation, you determine that acomplete inspectionsof the establishment should bemade contrary to rfie Area Director's directions, thencontact the Area Director and explain the situation.

Normally, employees may be represented on thewalkaround. This does not prevent you from talkingwith any employee who desires to discuss a possibleviolation, if it will not interfere with the conduct of theinspection. Upon receipt of such a communication._you should inspect for the alleged violation and recordany findings.

Hefore leaving to investigate an accident, you shouldtin all papers, documentl and other materials

needed for inspections.

3. DISCLOSURE OF INFORMATION DURINGINVESTIGATION

Ihe Department of Labor's:policy regarding the dis-closure rte documents and information "tram the files"is governed by the Freedom lqi)rmation Act.)SHA's policy is to disclose all documents to which

the public is entitled under the Act.

However. durigg Lh course of sin accident investi-gation, you must not provide any documents or infor-mation concerning the investigation to anyone. if news

trite to re presentativss or other interested personsrequest information irtvn you or question your-activi-ties, you must state only that an investigation is underway and that you are not pc/mitred to provide any in-formation,or documents until the findings have been

made. Then, about the specific case will breleased from the OSHA Regional Offiae. All requestfor information should be referred tti .the RegionalOffice.

dL YOUR -RELATIONSHIP TOOTHER INVESTIGATORS,

4

It is likely that there will be other investigators in-terested in the accident you are investigating. Theemay be investigators representing the State, county, orcity; insurance agents or others representing the owner,union. equipment manufacturers, or families of theaccident victims. BeCause of your expertise, you maybe called upon by these other investigators to advisethem on OSHA regulations which may be applicable.You should be able to provide this assistance withoutcommitting OSHA to specific actions that may not be

in consonance wit National Office or Regional Officepolicy.

Generally, the iv lice. fire department, or emergencyrescue squads are the first to'arrive at the scene of-anaccident. They usually conduct a thorough investiga-

tion and obtain valuable information which possibly

lay be helpful to you. Your main concern is to deter-mine if there have been any violations of the OSHAstandards, and it may be to your advantage to consultthe police and fire departments to obtain accurate andvalid inforation that may help you in making an

effective investigation.

C. The Courtroom Perspective,..i. . .

ec ttme aljldents you investigate are serious ones,there fs a good chance that the incident will end up incourt. If this happens, you may be called to testify as awitness. Therefore, you should always proceed verycarefully in gatheting your evidence during the in-vestigation. In technical matters for which you do trothave the required training or experience, you shouldrequest the assistance of a specialist.

All evidence must be well documented, so that thereis absolutely no doubt in a court proceeding about. hevalidity of your facts. If exhibits are not adequatelylabeled, if photographs and sketches do not corn;pletely cover the accident scene, or if your interviewstatements are 'not properly preparedif 'for any ofthese reasons your ealence and testimony might bedoubted, they may not be acceptable to the court.

Thus, in deciding whether to call for assistance or indeciding how to gather certain information, base yourdecisions on the assumption that what youdo d theinformation you gather will have to'be defe ed in

court.

Figire 2. OHOTO RAPHY LOG

DISTANCE TO

SUBJECTCOMMENTS

Place.

IL INNiESTIGATIVE TECHNIQUES

A. Site Documentation1. PHOIrOGRAPOING

Photography can serve as a valuable method ofrecording conditions dun may change during the in-vestigation or ihortly thereafter. It can also aid in pre-paring sour region and in analyzing conditiOns at thesite- of the accident. Photographs should always betaken; however, you must take precautions to assurethat the use of flash or spark -producing equipment willnot create hazards.

The employer should be notified during the openingconferderthat photographs will be taken during theinvestigation. In areas where confidentiality of-tradesecrets is involved, the procedures described below,shall be adhered to.

If the employer objects to the taking of any photo-graphs that you believe are essential to the investiga-tion. you should advise the employer that the regula-ttions (29 rFR 190.7 (b) specifically authorize takingor obtaining photographs related to the purpose of theinvestigation. Additionally, if the employer's objec-tion is based on the fear that trade secrets may be dis-closed. you should advise the employer of the protec-tions against such disclosures- afforded by the Act(Section IS), the regulations 129 CFR 003.9). and theField Operations Manual (Chapter V, paragraph13.6.h). Specifically, the employer should be advised, insuch cases, that under paragraph (c) of the above-cited regulations, all negatives and prints of photo-graphs taken in an area that contains or might reveal atrade secret shall be labled "confidential trade secret"and shill not be disclosed.

If the employer still objects to taking photographs,the investigation should prciteed without such photo-graphs and you should immediately advise your AreaDirector. If you and the Area Director jointlymine that photographs are essential to complete the in-vestigation, the Area Director should refer the matterto the appropriate Regional Solicitor with the requestthat a warrant be obtained'.

Photographs of the overall scene,, wreckageand pertinent hardware should he made prior tadjustments to the scene of the acei;r4-Worc-belp-ful in determining what,ha opened well as in provid-ing illustrations for reports. In instAnceswhere unusualwreckage patterns exist, color photographs are ofvalue. Two examples would he in differentiatingbetween smoke and oil discoloratio.ris or among sari-oos colored paint smears. Stereoscopic photographs ofbodies and detailed parts may, he "extol in the on esti-gation_

Before taking any pictures, should determine ifthe scene has been altered. If items have been alma orchanged, note what the alteration is and the person'sname referencing the change. Items rtiav have been a.moved to reach an injured person. to fight a fire, or t orother legitimate reasons,

e2

Decide before proceeanything, to preserve thare needed, make a listtake, dividing them into

mg what must be done, ifscene. Then:if photographsitems that you will want too groups:

I . Photographs of the-scene before moving anythingor adding anything

2. Photographs of the scene and eloseups with thescales and highlight markings in place

Each of the two grdups should include photographstaken at varying distances: overview, midrange, andcloseuP. Also, rernernberto photograph from Severalangles; quite,, often the camera Will catchteruf retainwhat the eye has seen and forgotten. Obtaining photo-graphs from different angles will require extra effort.The "fIr -cornered" approach (front, back, and twosides) usually will provide all needed angles. Eachphotograph should be numbered and the position ofthe camera and its directioq 'of vision should be indi-cated on a map or sketch. 'A ppcket compass will suf-fice for direction, and location may be obtained bypacing from some object shown °tithe Map. This pro-cedure is necessary primarily to reduce the measore-ment distortions of a camera lens. Sometimes it isnecessary to identify such items as piping, where sub-sequent identification from pictures can be incorrectunless the distances just referred to arc known. _

For closeups, use a rule (such as' a folding 6-footrule) next to the object to be photographed in order toprovide an accurate scale for the picture. lo some eases,it would be desirable to have the rule folded for boththe vertical and horizontal dimensions. Inphotography, a rule that displays fractions of feet ispreferable to one with inches, since it shows up muchmore clearly in the photographs.

When there is a great deal of photography, it isimportant to document- the pictures. As an aid to'recalling the many onsite pictures you will betaking, itis recommended that you use a logging device such asthe one presented as 'Figure 2. After the photographshave been developed, the following informationshould be written on the back of, or attached to, eachpicture:

OSHA-I Report Number, Area Number, RegionNumber

Employer's name and address

Location within plant. facility, or si

Date (month, day and year)

Time of day

Location of photographer or idenon a sketch of the area

Brief description of what phoidentify

Your signare and number

fying number

ph is try 'in

7

The original photographs and negatives shall he keptin the investigation file. If additional copies aredesired, consult the Area Director. Photographsobtained from other sources also should have all theabove information, as well as the name of t he source.

'2. SKETCHING ON DRAWING

Quite often it is more advisable to sketch or draw(rather than photograph) parts of the accident scene,especially if material has been destroyed or moved by-fire or explosions. Fhe following points will make t hejob a bit easier and provide the degree of accuracynecessary.

AISsays use squared (graph) paper, with the valuefor a square provided at the bottom of eachsketch.

Orient each area sketch with an arrow paintingnorth.

strip of the sq uared paper measuring anydiagonals on the sketch.

!important objects should he located by an

approximate outline.

Large objects are labeled inside their outlines,while smaller objects are identified outside theoutline with an arrow t o the object. ( Caution: t hearrow should just t ouch t he line.)

It you discover that you have too little space inw hich to put a label, use letters or some otherdent 'hers at the bottom of the diagram or on an

attached page

Indicate the distance of moa tile objects frofixed locations_

\ ote the location ofit the accident

tncsses present at the time

If the sk etch is used too nt photographs, t helocation and direction ci ch photograph s hou Idhe 'dent Med by a let ter or number and that'dent ifier placed on the back of the photograph.

etches should he identified on the back, usingthe same inf ormati on as for photographs.

B. I ntervlevIring1. GUIDELINES FOR CONDUCTING

INVESTIGATIVE INTERVIEWS

The-fundamental purpose of interviewing is to obtainan accurate and corn pre hen sive ac count rorn the per-son being inte rvie vied ot all pertinent facts, interpreta-tions, and op' mons t hat relate to the accident he i ng in-vestigated I 0 acciirnpl ish this ti hiectis e, the inter-viewer must conduct the interviews in a professionalmanner [ he person being i ntervie vied must be tree todescribe t he accident and provide other int ormationwit bout being influenced either hs t he inters ICA r's

persortalitxorthesettingin 11,1-n0 the inters less is tak-

ing place.

In mans- accident investigations, interviews ma-y' beyour primary source of information. It is important,therefore, that the interviews pe accomplished in athorough and efficient manner. The following guide-lines are presented for conducting interviews of thehighest quality:

Have a plan d know where the interview isgoing to lead. P are questions ahead of time, ifpossible.

Make sure you und and the technology of theequipment or t he process involved intheaccident.With this knowledge, you will not only ask betterquestions (to elicit more precise and relevantinformation). but you will also gain the respect ofthe person being interviewed.

Schedule the interviews so that you avoid ahurried atmosphere. Allow enough time to hearwhat the person being interviewed has to say.Some people are reluctant to talk until theybecome better acquainted with where the investi-gation is headed.

Fl old your interviews in private to avoid dist tar:-tions. Though a quiet room is best, you may haveto conduct the interview at the scene of the acci-

-, dent in order to have technical mat ters explained.Private interviews also emp hasize t hat vou rat tent ion is directed entirely at what the person beinginterviewed has to say.

Put the person being interviewed at ease. Avoidbeing overbearing in speech. voice, or man-nerism. Be careful not to talk down to the personor use language that is above his or her under-stand ing.

Avoid asking any questions that suggest anexpected answer and avoid questions that canproduce only "yes" or "no" answers. Above all.remember that your questions are for the pur-pose of obtaining information,

Let the person talk, but not ramble. Rat her. inter-rupt where necessary and turn the conversationhack to the subject at hand. Always keep controlof the interview.

For witnesses, divide the interview' into two parts:( I ) let the person describe what happened with noquestions, and then (2) ask your questions andhave the two versions written down. This assuresthat statements given have not been influenced bythe interviewer.

ose the interview in a courteous, but firm.manner. Encourage the person to contact you ifany other pertinent information comes to mind,

Record what was said during the inters less andwait until immediately after the inters Jew torecord sour impressions and judgments: I hispresents mixing Your own reactions wit h those cifthe person being interviewed.

2. DETERMINING WHOM TO INTERVIEW

Obviously, you must'know whom to interview in orderto start the investigative proceedings, and the bestplace to start is to ask the employer to develop a list ofnanes Ito be provided at the opening conference).Also, ask each person you interview for the names ofothers who were present.

Much of your investigation will consist of interview-ing. Some of the people inter-stewed may havewit nessed the accident/. Others may he able to provideonly one or two facts, such as work habits of theinjured, or the history of past troubles with equip-me nt. Do not predetermine that a person is not worthinttrnewing, especially if that person has indicatedthat he or she has something to say.

CONDUCTING A COMPREHENSIVEINTERVIEW

Thy he interview meets the criteria of being corn.pie te. correct , and pertinent. Your goal is to hear andrec (ird all t he information given. ft can be most ernhar.ras sing to discover later that one of t hose interviewedhad vital information which he or she di4 not givebecause you failed to ask the right questions. The bestint crsiewers use a simple formula that should "get it

all for you. That formula is to ask the six key guts-tio vs: Who? What? Where? When? How? Why?

'Mho was injured'' Who installed the equipment?s'ho was responsible for if' The nature of the acci-dent will determine the exact questions you should

what happened"' What did the people do? Whatequipment or facilities were involved' This line ofquestioning should lead sou into act ions, events,and rowsical objects.

Where each worker located' W here was theoserhead crane? Where was the firefighting equip,view' I he "where" questions have a way of helpingsou determine what caused the accident and cis-

-r the conditions that broughtla about

lkhen? r he tinswers to the -wher)questions shouldontain rook. information than a clock reading.lhough time is important, relationships are often

cien more important -When- questions often elicitinformation on relationships het een pairs of act iv_ititsor events

Cow? I-his type of question should provide int or-niation on the interaction and relationship amongt he acto{ft les and events (going besond their timingand int(NoTte functional relationships among them)"How" 41Testions refer not onls to the action tit

equipment but to action sit the injured as well.

V' A nswers to "wits -qr,tirinsshouldgistvou!some elites as to e(srreetive nrrtasur( since the an-mietti.v. II locus on unsafe acts or haiardoust ions.

r1F Vii!TfslocqrS

I he six basic questions provide the opening tor theinvestigation and the foundation upon which it canhedeveloped. There are, however, some poi nts t orerrietn-her about those being interviewed. They are Ilhu can

and, as such, are subject to human traits (king mis-

taken or misleading. withholding information or

exaggerating).Those concerned with an accident tend te-a be

satisfied that their duties and roles had been properlyperformed and that no act of theirs had anything t odawith causing the accident. However_ at the same tth-ere nay he an uneasiness in their mindsthatper tapsa thorough investigation will implicate them bee auseof some little act of commission or omission on theirpart. Therefore. they may be quite willing to let the

matter drop without getting involved in artyreaalin.vestigation or be somewhat misleading in the itnter-

view, in order to protect themselves.Additionally, there is the problem of how pe-ople

regard investigators. The objective of most inveft 1iga-tionssuch as those conducted by insurance claims.agents and detectivesis to determine who isatTo overcome reluctance (or even open hostility), youmust impress upon all those you interview that yourobjective is to gather data to serve as a basis for pre

venting future accidents-Remember, when taking statements from vitne sses,

do not assume that the information is always valia.Nomatter how honest they may be. witnesses aceouritsofthe accident will inevitably be colored by i ndivi dualpersonality and perspective. In fact, where you find

total agreement among witnesses, the witnesses may

have talked over the situation previously. In this case,you should listen to each and record his or her

statements. Then, listen to their conversat ions with

each other for points of disagreement.Since accidents typically occur with little forewarn'

ing, witnesses are not prepared for than. Con-sequently. they observe only a few key points and

imagine the rest, With this in mind, do not he sur-

prised if some witnesses realize, duringt he re stagi rigofan accident, that they could not have seen a II of vitalthey reported to you.

We all recall the tale of the six blind rner and theelephant. All of them were telling the truth ahou ttheelephant. Each. however, emphasized the fact yvhichimpressed him about the elephant each had oriI apart of the entire picture. Your ioh in the invt stigtionis to construct a composite "story" using the variousaccounts of the accident and other evnjenec.

Sonic rapport can and should he estahli shedbetween you d the person being interviewed.A goodpractice is to keep the person's name rate nsuch a manner that you can refer to it during the t verstew. Also, if you can gather a little preliminary mato-

mation about t he person to he inters iessed. sou mils

determine the reasoning hchind his or her ans ssers Ihe

safets supers isor is likely to see an a cod ent r in;in

entirely different v. as than the floor supers istir The

worker. who max feel that he or she is in, sonic, sias

responsible for the accident, max he quite re toms 11110

4

speak about it Consider s4 here theheld tat the scene of the accident, its a hospital 1,ww,employee's _home, or the efrIplo!,ces. lounge). It posse=

vou should interview each person alone.

5. 'PREPARING STATEMENTS

ry to obtain a statement from each person whinterview. Statements provide a record for our investigatise report and may he used to ref resh the think-ing of those Interviewed, as well as of the ins estigators.Statements should he signed it possible, but employ ccsignature is not required,

Statements taken during the interviews should he ina form that will he useful. Statements should he clear,brief, but complete. Remember, you will he writing areport from these statements later, and you may heto use them in court, I i; avoid misunderstandings, thestatement should he read tvo the person w ho has gas en itto you

I hough statements should be written at the time ofthe niters few, a tape recorder mas he used when cir-cumstances warrant it If a tape recorder is used theconversation should he transcribed and the transcrip-tion should meet the requirements of the e'dOperanon,s Manual. Chapter I I he statement shoulduse mans of the actual words and phrases ofithe personWho gage it. Since the sequence ot es ents is important,make sure the written statement agrees with what theperson had to sits. If there are mistakes in the preparedstatement, do riot erase, Instead, draw a line throughthe incorrect words and write in the corrected wordsFor statements that are signed, es cis change must alsohe initialed ris the person go. ing the statement

6. ANALYZING THE TESTIMONY

Before using testimony reach conclusions, the in-sesngator should determine how much salad, tactualevidence it contains and how much of the mtormationis conflicting, For accidents in clear stew of allwitnesses, this lob may he a relaus els simple one, sincethe prohabilits of conflicting tesnmons to such cases isunlikels

On the other hand, where the circumstances arecomplex and where.alashic number ot conflicting state-ments has e been taken. the investigator must caret rillsreview and evaluate the testimons ()rats substantiatedtestimony should he retied upon m the final anal,. sis

C. Accident Scene Examination1. SAMPLING

I here are mans reasons tear taking saniple, of materialsduring an accident investigation. Samples mas resealthe cause of death or injury

In cases w here it is suspected that some mechanicalOr structural Failure comnhuted to the accident. sotsmay wish to take samples of soil, concrete, or parts 01machl non,. suspected of failure .Samples of materialstaken from the scene may I, for example, that in-

It)

01 a huildingtrench or excas anon case-m.

In cases where violations of health standards are thesuspected cause of fatalities or casualties, you may findit necessary to take air samples or other samples tocheck for the presence cat impurities or toxic sub-stances I hese samples may show the presence ofharmf ul gases such as chlorine or carbon monoxide orof dangerous particulate matter such as asbestos dust.

You will find sampling procedures and updatedOs flA collection procedures in the held Operations.1lanual and Program Directives 1-or Industrialhivrinene Procedureso4

L

(Ins ahlr sod Bern iatris led to

2. LABORATORY ANALYSIS

I aborators analysts of samples talin during an acci-dent insestigation is usually performed. Aft thesamples have been collect and all appropri. paper-work has been completed, samples. wh are to bechemical's analsied, such as air or dust samples, musthe packaged and shipped by certified mail to theOSHA Analytical Laboratory in Salt Lake City. Firspecific instructions on obtaining laboratory analyseson samples sent to Salt Lake City, consult theIndustrial Illgiene held Operations Mama/,

As a general rule, structural and mechanical_analyses are performed either at a local independentlaborators or at a Gosernment laboratory, dependingon area and regional polies_ You should, of course, 1 ol-low. the normal procedures in sour area for obtainingthese analyses,

D. Other ConsiderationsIn addition to the major techniques and appr. ache tohe einplosed in carrying out an investigation, there arcses eral other, more specialised aspects of investiga-tion with which sou should be familiar. Each of these ispresented in this final portion of Section II,

rf1. WEATHER

In some msestaganons, the weather volt be animportant factor in determining the possible causes ofto accident. It Is therefore important that you estab-lish exact's wrh,t the conditions were at the time of theaccident. For example, an individual could havereported seeing a flash of lightning before beingknocked unconscious, vet a check with the weatherbureau might confirm that the weather conditions fort hat das could not have produced lightning. One couldconclude that the worker actual'y had observed an ex-plosion.

\\eat her conditions can direct'y affect worker per-t ormance or can lead to the use of certain equipmentwhich, in turn, may start the chain of events leading toan accident For example, flash flooding may causeworkers to use a pump histore properly checking itssatcts teat ures

('leads, the weather can cause or contribute to aces-dents In sour ins esugat ion, do not omit the weatherand its possible role in the accident,

2. ARE

If an accident insolyes a lire, it is of the utmostimportance that you determine the e.\ act nature ot thefire. Was the fire started as a result of the accident? Inthe case of explosions, did the fire cause the esplo-sion? Did the overloading ot an electrical Qat:till w,:t re=SUR of malfunctioning equipment cause the lire"

Most fire departments hase personnel skilled indetermining the cause ot a tire. llowe\ er, the es (duncemay be buried for some time, ho:h literalk and ligur,i-tively. Before the analysis and final report are .ono=Meted, you must know exactly how thel He Ids into theoverall sequence of events Do not (1\ erlook the tietthat the tire and the materials used to put it out cansubdue or hide e\ idenee

Additional information on tire nits totind in tl,eNational hrc Codei and 'Sanonal hie Pr,itec thinIlandh(wk published hs the \ ational hire ProtectionAssociation his all means consult these codes, Iii the\can be of help.

3. FATALITIES

Persons killed in an accident fn III!of the most inform:doe sources ref e 1.1( ,it the sceneof the accident. For esample, the ieport tiltsIderillh both the cause ot death and other unusual con-ditions or iniurics present thi±righ not significant in thetatalm. maims linding such as heart Judi, k foreigngases in the bloodstream. or embedded Metal triw=merits, will ph, a signituani tole in \accident's chain 01 0. ems, 4, \1/4 ell 71, and Li H'trihuting factors

, i; , i,,nei ;1,1i 1, ,i)i teal, lialiilof the pci NOM sI nho, hcs,ignift.;,tut elUCs in the

msestigation For evamplc, the\ nits help to deter-'nine the relationship het\keen tyre and explosion (aswas mentioned abuse) or whether the persoMs I was

.mpting to asold a worse disasterIn the case of each tatalitv, it is essential that sou

determine much is possible about the deceased's lobresponsibilities, operating procedures, skills, andshortcomings I his Infor mation is important in deter-mining the relationship of each indo.idual to the acci-dent. In sour inyestigation, no should always keep inmind that the person could hays:

t_ aused the accident,

Been an unaware hvstander, or

Been attempting to prevent the accident or limitits effects.

I hough sour most important Ovewitoesses alas havebeen killed in the accident, information ahou themand !nun autopsies r e saluable.

4. RECORDS

I here ,ire several types records that may pros ideconsiderable amount of es idence. In addition to co m -ram records of personnel involved (particularly forthose there are of ten logs kept of sensitiveoperations or prOcedUres, aN well as "signoll sheets "tomaintain aceounta hilts, among personnel, main-tenance records for eLf inprrfent, ett.

An integral part of your investigation should there=tote locus on gathering .ind analviing all reco,rds thatnuo possihlt cont nbute to determining the accident'scauses

ill . ANALYSIS AND REPORTI149

A. Causal Factors AnalysisCauses can he determined only through proper in-yestigation to ascertain all factors that contributeddirectly or indirectly to the disaster. Fhe investiga-tion's findings will reflect on the thoroughness andeffectiveness with which sou collected evidence andproperly analyzed it.

Deductise reasoning, which begins after disclosureof the basic facts and continues through the process otanalysis, should he the basis for all investigative find-ings It may be necessary to resort to a process ofelimination to arrive at conclusions as to what hap-pened.

An often os erlooked but important hs product ot in-sestigations is the identification of potential causes ofother accidents in the future such factors mas havehad little to Jo with the accident being msestigated,howeser, the inestigator should he alarre that suchfactors do exist and often precipitate future accidentsof greater magnitude I he inestigator's report shouldinclude recommendations for corrective action to eli-minate the Ide'ntifie'd potential causes 01 lottircaccidents

1. ANALYTICAL TECHNIQUES

I he Iollovong paranaphs des,:rihe some it the

approaches that ean he used tor orals /mg the gatheredcs idence

As earls as [loss, ble al ter e illect ing the es idence, s oushould dekelop a ehndroloo tit eents leading to theaccident I his may he accomplished hs using record-ings. telemetry data. test procedures. logs. testimons,4nd other pertinent data obtained or impoundedearlier l-*rieh bole = has- e,..iuence iit es erns is an in-

aluahle tot .11 for

,1 IINtantiatm14 c\ [den

Pointing out speellic area v. here detailed

examination needed, and

causal factors.helow

1.; Ill he described

I he concept of "know n precedent' should he kept inmind during analsos I his concept is based on thetheory that es ents yei ii repeat themsels es, gis en enoughtrials V* hen applied to insesugation, actual prece-dent, tie , causes of pro toils similar accidents) pro-s idea 'Iasi. for Itoels1, identilving tentative causes ofthe accident under iris estozation Such tactors as pre=s isms accident reports, hazards analssis, and failurehistories mas proside precedents to the tiserallaccident, or to stone specific aspects it it I he searchfor know n precedents should include not onls the his-tors of the operation in question, but also the histories

of similar types of operation,

Alter an investigation of an accident of even modestcomplexity, you can expect to have accumulated agreat deal of information in the form of interviewstatements, photos and sketches, lab reports, medicalreports, etc. In preparing your analysis (and in pre-senting the evidence in Our investigative report), youshould develop a framework for organizing your in-formation.

Everything that can be seriously considered as a pos-sible cause should he explored and evaluated. It alsowould be helpful, therefore, to employ logic models, inorder to insure that all facets of the problems are givendue consideration. One or more of the hazard analysesmay he used in constructing causation models anddeveloping recommendations. Through the use oflogic models, causal factors and recommendations forcorrective action may be categorized hs- areas in whichdeficiencies exist (or are presumed to exist? A sug-gested approach to constructing a logic model is to:

Select the line of reasoning to he followed.

Pose hypothetical causes and corrective actions,and

l est these hypothetical cauexamination of eydence

through

1 he investigator will find that the traditionalprohlem-sofa mg technique of posing hypotheses anddoeloping them to the point where they are prosed ordisproved is an effective means ot arriving at mishapcauses Initially, data should he collected to supportthe hypotheses. The data should he checked foraccuracy and thoroughly analyzed in relation to thehypotheses in question. I he logical consequences ofthe data are tested through comparison with actualconditions, therehs validating or invalidating theh\potheses

2. THREE TYPES OF CAUSES

I he causes of an accident are actually ci,nihrnatiiin ofsimultaneous and sequential circumstances. all ofwhich must have been pait for the accident tohappen. Any circumstance contnbuies to an acci-dent may he spoken of properly as one of the causes ofthe accident. making it only one circumstanee of acombination._ lore specifically, a cause of an accidentis any hehavior, condition, act, or negligence without

Filch the acident would not have happened. Hence,in seeking causes of an accident, remember that anaccident may he the result of the interaction amongot herwise innocuous conditions and es ents

Since You are concerned with all unsafe conditionsand practices involved in each accident, sou cannotproperly talk about "the cause" of an accident Investi-gators who come up with a single cause may has e con-ducted an inadequate investigation and anaksjs.

13

Although there mat he.r prtdoiniii trii ',whir r.. iep 110it as the wilt factor int ols ed m the aeudcnt Hten he either scientific or professional Such think ingcontributes tert little to understanding him the aLcident might have been pretented

Adverse circumstances are other factors that mat hepresent, without necessarth emu tibuting to a go. enaccident. It is not alwats east to determine w hethetobtiousk untatorahle cireurnstance actualk contrib-uted to an accident For example. w hilt intoxication isan important factor m some chicle accidents, theremat he times when the di is er's intoxication is not thecruse -of the accident A sober (inter mat drisevehicle into the rear of one operated bt drunkendoter who had quite properly stopped his or her \chi-cle at a traffic signat I he drunken driser should hearrested for intoxication. but the accident might hateoccurred et en if he of she had been ,ompletek soberDrunkenness did not necessarily cause the accident.and simple finding a trattu snatation lbitingtoss ;itedl Wright not he considered a tomplete int esti-gallon tot causes of the accident

In order to get ,swat II orn the idea that most accrdents hate a single cause. there .s need tor specificguidance in defining and identd dig accident causesSuch guidance will help sou to improte t our intesti-gation and ensure better anal\ sis, and set the stage tormore appropriate recommendations for correcro,caction I'M these purposes, k. auses can he i=lassit led intothree easily recognilable letS, direct, IndlICLt andcontributing I stirs accident is the result of at least onedirect and uric indirect and some ,i,odents Matt-'man\ it each I hese hr it described below

Direct (ruses I hese are usa, t e act, (doing s, ure-thing or lading to do something specified hit Iris titdictated hs site practicesi that hrought ahout !hr.:acci-dent "1 nsate,- tr this purpose include,- iius that nuunusual, unexpected. improper moral Jou,I \ample. of direct causes are

I .)perat mg at a speed IP I rT

for existing ,ns

Laming rate +n material

Mutual inter-ter idia

\IIItion relatite that ,-C,ItCN Li

haiardous sduai.on

apacitt titerl,i,id Ihurrlari or inaLharail

Inattention, which in turn pre\ ents sueltessiulet ask e action under the ChHting c, +ndlt ion,

I milts corrective t takes Hid or tomitigate an impendingwas pereeited

Indirect ( muses I Vies tips cri, iridesirregular Or unusual conditions that txlll, tin tiahs theprincipal element (person or equipment i oionti-ihuteLtdirect cause to the accident Indirect caiste arenetted to the accident through the dire r

samples of indirect causes are

14

I t,,-sd..11,_ (lire, I III L

the accident 1 Heine'tderit

I nusual conditionstrots, or terrain

L11 'lit pi [,/Pt( / it tt /fit rite-'

thrut \

at her, . ri=

Condition., trf p r mnel hs far the trit).t 11=

run twe fl tdirect cause including IIIpermanent thou_.:` correctaFlleconditto ns, such aspoor etesight, certain kinds of k now I=

edgeor pstch logical faults, and (2.) temporartconditions, su has intoxication. pht sk,ral exhaus-tion, or cart tlnal upset

( ontributing uses Accidents also hate contrib-uting causes, al tf which are acts of negligence on thepart of sortie trson or orgamiation not directltintuited in th accident Some examples are inadequ-ate codes at standards, lack of polies. failure ofsupervisors i perform their duties, lack of enforce-ment, fautt design or inadequate maintenance, in-adequate t ming, and lack of satets training

o atm accepting the first cause as the onk causesbecause t usuallt is the most apparent theinsesttga or should strite toward the more elles.rtii-oz

cause concept where rill the factors in-k-Olt.edire kn n and considered I he multiple-cause con-cept riroses investigation techniques and ensure=shen r Amid\ sits. and sets the stage for more Accurateand mprehensite corrtctis e action

3, SOURCES OF FAILURE

s.;, ou sort ut a l l the et idence In sea.rch of the com-bination of es ents and circumstances that hroughtyaftout the accident, i t mat he useful t i c kinsider set erar

ssihle tsrves-oi deficit:no, In ant particrilarbent. causal (actors will he found in one or more of

/these areas

Ilidnan 1-04Yure I his categor% inClUdesphtI ph% siological. and psychological limitations An

example is the !inane to follow apprised check-lists of to tallow the use of authorlied proce-dures techniques I he eategort also cot ersfactors associated with Imitations suchas illness and blackout and cis\ etiologicalproblems such as claustrophobia Human factorsmat be underling or well hidden and becomeapparent or It ;if ter a caret ul et aluation I hefailure of a person to perform an act mat be class i=tied as a _human t tilure. although it rnas not hepossible to determine v.h\ he or she tailed to perhIrm it

I t . Int, al Data I his Lit:filen:noesuits trom use it inadequate technuai data,

operating inst.- 'trims, omissions. cif errollemlr,data

I iirktiririi 11,i/ 1 1,71, (

or deticieni,ies, an, eiroanifsus tt hen an e'er-Faint r-nanage-

ir int ributed to the mishap

because of inadequate planning, supers ision.training, or work practices.

Material FailureThis is defined as the physicalbreakdown-or chemical deterioration of any part,structure, or component.

Design Deficiency -Though sometimes difficultto differentiate from material failure, a designdeficiency exists if a part or component is sodesigned that failure can occur under predictablecircumstances.

Natural Phenomena -Defined as acts of nature,this deficiency area does not apply when there isevidence of failure to take normal precautionsagainst these contingencies.

In the final step of analysis, it would be useful toreexamine your thinking in terms of types of causesand sources of failure.

B. Reports PreparationThe final step in the accidknt investigation procedure isthe preparation and subtnission of your final repon.Because the forms to be used change from time to time,they are not listed here. Consult the Field OperationsManual for the proper forms to be used and forinstructions for completing them.

15

IV. SUMMA

Throu- _out your InveOngation of an accident, therearc two goals you sh 14 always keep in mind ( I) toerfind out what-hap ed and why, and (2) to prevent itfrom happening again' What has been presented in thispublication constitutes a handy reference or manual tohelp you achieve those two goals. You should have itavailable at all times; it c3n.help you by referring you tothose steps that must beperformed in order to deter-mine what act, whethermechanical or human, or acombirtation,`caused or contributed to the accident.Your investigation will, hopefully, help to correct thesituation and help to prevent further accidents fromoccurn ng.

This manual, then, is a summary of the morecomprehensive steps and procedures you must followduring your investigation. It provides you with a guide-line toward helping you plan. prepare, and execute aninvestigation of the workplace.

Briefly, it has covered the following points, whichcould serve as a quick checklist for vou ciRuring your in-yestigat ion.

16

) File and history on workplace and related orsimilar cases

) Special equipment to he used

) f he opening conference

) Walkaround of the workplace

) Administrative support

) Documenting the scene

) Preserving

Interviewing -ses

) Fhe closing conference

e evidence

) Preparing and submitting report

However, for specific instructions or information,you should refer to your Field Operations Manual,051/A Program Directives, and other pertinent infor-mation on the subject of accident Investigation.

S. .0C3VERNMAILIAT F150-1T_ OFFICE 1417 /41-.0141S1