Best Practices in Accident Investigations

Published On: October 18, 2023By Categories: Safety, Safety Matters

Investigations are designed to prevent further occurrences, not place blame.

By Alexandra Walsh

Accident investigations must be done when there is a fatality, injury, illness, or a near miss. An accident is an unexpected event that results in an injury or illness. A near miss is also an unexpected event but does not result in an injury or illness.

Why Investigate?

When incidents are investigated, the emphasis should be on finding the root cause of the incident so a company can prevent the event from happening again. The purpose is to find facts that can lead to corrective actions, not to find fault.

As a best practice, always look for deeper causes, and do not simply record the steps of the event. The reasons to investigate a workplace incident include to:

  • Find out the cause of incidents and to prevent similar incidents in the future
  • Fulfill any legal requirements
  • Determine the cost of an incident
  • Determine compliance with applicable regulations (e.g., occupational health and safety, criminal, etc.)
  • Process workers’ compensation claims.

The same principles apply to an inquiry related to a minor incident and to the more formal investigation of a serious event. Most importantly, these steps can be used to investigate any situation to prevent an incident.

Reacting quickly to the incident with a prescribed procedure and actions can demonstrate a company’s commitment to safety and ensure the proper information is collected to fulfill an incident investigation’s ultimate purpose—to prevent future incidents.

The purpose of fact-finding is to determine all the contributing factors to why the incident occurred.

What Are First Steps?

According to the National Safety Council Alliance, the investigation process should begin after arranging for first aid or medical treatment for anyone who is injured. In getting started, everyone involved—especially workers—should be reminded the investigation is to learn and prevent, not find fault.

Steps of the investigation process include:

  1. Call or gather the necessary people to conduct the investigation and obtain the investigation kit.
  2. Secure the area where the injury occurred and preserve the work area as it is.
  3. Identify and gather witnesses to the injury event.
  4. Interview the involved worker.
  5. Interview all witnesses.
  6. Document the scene of the injury through photos or videos.
  7. Complete the investigation report, including determining what caused the incident and what corrective actions will prevent recurrences.
  8. Use results to improve the injury and illness prevention program to better identify and control hazards before they result in incidents.
  9. Ensure follow-up on completion of corrective actions.

Why Document?

As with many processes, preparation and documentation are crucial. As part of the injury and illness prevention program, the investigation procedure should detail:

  • Who should conduct and participate in the investigation
  • Incidents to be investigated
  • Information to be collected
  • Identification of causal factors (root causes)
  • Determination of corrective actions
  • Tracking completion of corrective actions.

Who Is Involved?

The investigation is typically conducted by the injured worker’s immediate supervisor. However, assistance can also be provided by a safety supervisor if the company has someone working in that capacity, or team members from a safety committee if these teams exist.

In cases involving a fatality, senior management and legal counsel may also be involved. Those participating in the investigation would include the injured worker, witnesses to the incident or events preceding it, and the injured worker’s immediate supervisor if some other person is conducting the investigation.

What Gets Investigated?

Any incident resulting in a fatality, serious injury, or damage to property, equipment, or environment should be thoroughly investigated. To obtain the best possible data to aid in predicting and preventing future incidents, it is a best practice that all recordable first aid and near miss/close call incidents are investigated.

What Information Is Collected?

The type of information that should be collected during the investigation process includes:

  • Worker characteristics (age, gender, department, job title, experience level, tenure in company and job, training records, whether they are full-time, part-time, seasonal, temporary, or contract)
  • Injury characteristics (describe the injury or illness, parts of body affected, and degree of severity)
  • Narrative description and sequencing of events (location of incident; complete sequence of events leading up to the injury or near miss; objects or substances involved in event; conditions such as temperature, light, noise, weather; how injury occurred; whether preventive measure had been in place; what happened after injury or near miss occurred)
  • Characteristics of equipment associated with incident (type, brand, size, distinguishing features, condition, specific part involved)
  • Characteristics of the task being performed when incident occurred (general task, specific activity, posture, and location of injured worker, working alone or with others)
  • Time factors (time of day, hour in injured worker’s shift, type of shift, phase of worker’s day such as performing work, break time, mealtime, overtime, or entering/leaving facility)
  • Supervision information (at time of incident whether injured worker was being supervised directly, indirectly, or not at all and whether supervision was feasible)
  • Causal factors (specific events and conditions contributing to the incident)
  • Corrective actions (immediate measures taken, interim or long-term actions necessary).

How Are Interviews Conducted?

Interviewing injured workers and witnesses requires reducing their possible fear and anxiety and developing a good rapport. Interviews should follow these steps:

  1. Conduct the interview in a quiet and private place.
  2. Use open-ended questions.
  3. State the purpose of the investigation and interview is fact-finding, not fault-finding.
  4. Ask the individual to recount their version of what happened without interrupting. Take notes or record their response.
  5. Ask clarifying questions to fill in missing information.
  6. Reflect back to the person interviewed the factual information obtained. Correct any inconsistencies.
  7. Ask the individual what they think could have prevented the incident, focusing on the conditions and events preceding the injury.
  8. Thank the witness.
  9. Finish documenting the interview.

How Are Causal Factors Determined?

The purpose of fact-finding is to determine all the contributing factors to why the incident occurred. Statements such as “worker was careless” or “employee did not follow safety procedures” don’t get at the root cause of the incident.

To avoid these incomplete and misleading conclusions in your investigative process, continue to ask “why?” as in “Why did the employee not follow safety procedures?” Contributing factors may involve equipment, environment, people, and management.

Questions that help reveal these may include:

  1. Was a hazardous condition a contributing factor?
    (Defects in equipment/tools/materials, condition recognized, equipment inspections, correct equipment used or available, substitute equipment used, design or quality of equipment)
  2. Was the location of equipment/materials/workers a contributing factor?
    (Was employee supposed to be there, sufficient workspace, environmental conditions)
  3. Was the job procedure a contributing factor?
    (Written or known procedures, ability to perform the job, difficult tasks within the job, anything encouraging deviation from job procedures such as incentives or speed of completion)
  4. Was lack of personal protective equipment (PPE) or emergency equipment a contributing factor?
    (PPE specified for job/task, adequacy of PPE, whether PPE used at all or correctly, emergency equipment specified, available, properly used, function as intended)
  5. Was a management system defect a contributing factor?
    (Failure of supervisor to detect or report hazardous condition or deviation from job procedure, supervisor accountability understood, supervisor or worker adequately trained, failure to initiate corrective action).

Corrective Actions

Once information is gathered and the involved worker and any witnesses are interviewed, the investigation report is prepared and corrective actions formulated.

The company should have determined whom the report is sent to, within what time frame, and what information gets communicated to workers or management, and what gets filed or posted. Each corrective action listed should have a person assigned ultimate responsibility for the action, a completion date set, and a place to mark completion of the item.


Having a safety program that investigates accidents and incidents in this manner should reduce the number of workers getting hurt on the job—the goal for everyone involved.

Alexandra Walsh is the vice president of Association Vision, a Washington, D.C.–area communications company. She has extensive experience in management positions with a range of organizations.

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