• What is an accident and why should it be investigated?

    The term ‘Accident’ can be defined as an unplanned event that interrupts the completion of an activity, and that may (or may not) include injury or property damage.

    The term ‘Incident’ refers to an unexpected event that did not cause injury or damage but had the potential. “Near miss” or “dangerous occurrence” are also terms for an event that could have caused harm but did not.

    When accidents are investigated, the emphasis should be concentrated on finding the root cause of the accident rather so you can prevent it from happening again. When the root cause is determined, it is usually found that many events were predictable and could have been prevented if the right actions were taken. The purpose is to find facts that can lead to actions, not to find fault. Always look for deeper causes. Do not simply record the steps of the event.

    Reasons to investigate a workplace accident include:

    • most importantly, to find out the cause of accidents and to prevent similar accidents in the future
    • to fulfill any legal requirements
    • to determine the cost of an accident
    • to determine compliance with applicable safety regulations
    • to process workers’ compensation claims

    Incidents that involve no injury or property damage should still be investigated to determine the hazards that should be corrected. The same principles apply to a quick inquiry of a minor incident and to the more formal investigation of a serious event.

  • Who should do the accident investigating?

    An investigation should be conducted by someone experienced in accident causation and investigative techniques; as well as be fully knowledgeable of the work processes, procedures, persons, and industrial environment of a particular situation.

    In most cases, the supervisor should help investigate the event. Other members of the team can include:

    • employees with knowledge of the work
    • safety officer
    • health and safety committee
    • union representative, if applicable
    • employees with experience in investigations
    • “outside” expert
    • representative from local government
  • Why look for the root cause?

    An investigator who believes that accidents are caused by unsafe conditions will likely try to uncover conditions as causes. On the other hand, one who believes they are caused by unsafe acts will attempt to find the human errors that are causes. In fact, it is often a combination of numerous factors which led to a preventable accident or incident. Therefore, it is necessary to examine some underlying factors in a chain of events that ends in an accident.

    The important point is that even in the most seemingly straightforward accidents, seldom, if ever, is there only a single cause. For example, an “investigation” which concludes that an accident was due to worker carelessness, and goes no further, fails to seek answers to several important questions such as:

    • Was the worker distracted? If yes, why was the worker distracted?
    • Was a safe work procedure being followed? If not, why not?
    • Were safety devices in order? If not, why not?
    • Was the worker trained? If not, why not?

    An inquiry that answers these and related questions will probably reveal conditions that are more open to correction than attempts to prevent “carelessness”.

  • What are the steps involved in investigating an accident?

    The accident investigation process involves the following steps:

    • Report the accident occurrence to a designated person within the organization
    • Provide first aid and medical care to injured person(s) and prevent further injuries or damage
    • Investigate the accident
    • Identify the causes
    • Report the findings
    • Develop a plan for corrective action
    • Implement the plan
    • Evaluate the effectiveness of the corrective action
    • Make changes for continuous improvement

    As little time as possible should be lost between the moment of an accident or near miss and the beginning of the investigation. In this way, one is most likely to be able to observe the conditions as they were at the time, prevent disturbance of evidence, and identify witnesses.

  • What should be looked at as the cause of an accident?

    Accident Causation Models

    Many models of accident causation have been proposed, ranging from Heinrich’s domino theory to the sophisticated Management Oversight and Risk Tree (MORT).

    The simple model shown in Figure 1 attempts to illustrate that the causes of any accident can be grouped into five categories – task, material, environment, personnel, and management. When this model is used, possible causes in each category should be investigated.

    Figure 1: Accident Causation Figure 1: Accident Causation

    Task- Here the actual work procedure being used at the time of the accident is explored.

    Material- To seek out possible causes resulting from the equipment and materials used.

    Environment- The physical environment, and especially sudden changes to that environment, are factors that need to be identified. The situation at the time of the accident is what is important, not what the “usual” conditions were.

    Personnel- The physical and mental condition of those individuals directly involved in the event must be explored. The purpose for investigating the accident is not to establish blame against someone but the inquiry will not be complete unless personal characteristics are considered. Some factors will remain essentially constant while others may vary from day to day.

    Management- Management holds the legal responsibility for the safety of the workplace and therefore the role of supervisors and higher management and the role or presence of management systems must always be considered in an accident investigation. Failures of management systems are often found to be direct or indirect factors in accidents.

    This model of accident investigations provides a guide for uncovering all possible causes and reduces the likelihood of looking at facts in isolation. There is considerable overlap between categories; this reflects the situation in real life.

  • How are the facts collected?

    The steps in accident investigation are simple: the accident investigators gather information, analyze it, draw conclusions, and make recommendations. Although the procedures are straightforward, each step can have its pitfalls. Preconceived ideas and beliefs may result in some incorrect assumptions and leave some significant facts uncovered. All possible causes should be considered and conclusions should not be drawn until all the information is gathered.

    Physical Evidence

    Before attempting to gather information, examine the site for a quick overview, take steps to preserve evidence, and identify all witnesses. In some situations an accident site must not be disturbed without prior approval from appropriate government officials such as the coroner, inspector, or police. Physical evidence is probably the most non-controversial information available. It is also subject to rapid change or obliteration; therefore, it should be the first to be recorded.

    You may want to take photographs before anything is moved, both of the general area and specific items. Later careful study of these may reveal conditions or observations missed previously. Sketches of the accident scene based on measurements taken may also help in subsequent analysis and will clarify any written reports. Broken equipment, debris, and samples of materials involved may be removed for further analysis by appropriate experts. Even if photographs are taken, written notes about the location of these items at the accident scene should be prepared.

    Eyewitness Accounts

    Although there may be occasions when you are unable to do so, every effort should be made to interview witnesses. In some situations witnesses may be your primary source of information because you may be called upon to investigate an accident without being able to examine the scene immediately after the event. Because witnesses may be under severe emotional stress or afraid to be completely open for fear of recrimination, interviewing witnesses is probably the hardest task facing an investigator.

    Background Information

    A third, and often an overlooked source of information, can be found in documents such as technical data sheets, health and safety committee minutes, inspection reports, company policies, maintenance reports, past accident reports, formalized safe-work procedures, and training reports. Any pertinent information should be studied to see what might have happened, and what changes might be recommended to prevent recurrence of similar accidents.

  • Making the analysis and conclusions?

    Investigating most of the facts about what happened and how it happened takes considerable effort to accomplish but it represents only the first half of the objective. Now comes the key question–why did it happen? To prevent recurrences of similar accidents, the investigators must find all possible answers to this question.

    All possibilities and pertinent facts must be reviewed. There may still be gaps in understanding the sequence of events that resulted in the accident and further investigations may be required to fill these gaps in knowledge.

    • When your analysis is complete, write down a step-by-step account of what happened (your conclusions) working back from the moment of the accident, listing all possible causes at each step. This is not extra work: it is a draft for part of the final report. Each conclusion should be checked to see if:
    • it is supported by evidence
    • the evidence is direct (physical or documentary) or based on eyewitness accounts, or
    • the evidence is based on assumption.

    This list serves as a final check on discrepancies that should be explained or eliminated.

  • Why should recommendations be made?

    A set of well-considered recommendations designed to prevent recurrences of similar accidents should be developed following the conclusion of the investigation. Recommendations should:

    • be specific
    • be constructive
    • get at root causes
    • identify contributing factors

    Never make recommendations about disciplining a person or persons who may have been at fault. This would not only be counter to the real purpose of the investigation, but it would jeopardize the chances for a free flow of information in future accident investigations.

    Always communicate your findings with workers, supervisors and management. Present your information ‘in context’ so everyone understands how the accident occurred and the actions in place to prevent it from happening again.

  • What should be done if the investigation reveals human error?

    A difficulty that has bothered many investigators is the idea that one does not want to lay blame. However, when a thorough worksite accident investigation reveals that some person or persons among management, supervisor, and the workers were apparently at fault, then this fact should be pointed out. The intention here is to remedy the situation, not to discipline an individual.

    Failing to point out human failings that contributed to an accident will not only downgrade the quality of the investigation. Furthermore, it will also allow future accidents to happen from similar causes because they have not been addressed.

    However never make recommendations about disciplining anyone who may be at fault. Any disciplinary steps should be done within the normal personnel procedures.

  • How should follow-up be handled?

    Management is responsible for acting on the recommendations in the accident investigation report. The health and safety committee, if you have one, can monitor the progress of these actions.

    Follow-up actions include:

    • Respond to the recommendations in the report by explaining what can and cannot be done (and why or why not).
    • Develop a timetable for corrective actions.
    • Monitor that the scheduled actions have been completed.
    • Check the condition of injured worker(s).
    • Inform and train other workers at risk.
    • Re-orient worker(s) on their return to work.