Article

Workplace accident investigation policies

An accident investigation policy must state which situations must be investigated, when the investigation should occur, the purpose of the investigation, and how investigations will be conducted. Implementation of these policies may differ depending on the type and severity of a particular accident.

Key principles of accident investigation:

  • That the primary or underlying cause (root cause) of the accident and its contributing causes are discovered.
  • Taking corrective action for every accident cause that is discovered in order to prevent recurrence. Assign a person to be responsible and a completion date to each corrective action. Assign someone from management to follow-up on corrective actions to ensure that each action is accomplished on time.
  • Communicating accident findings to all employees when completed along with program changes that result from corrective actions.
  • Determining if training or retraining is necessary to prevent future occurrences.

Those conducting the investigations should be trained in investigation procedures, securing and protecting evidence, gathering facts and interviewing witnesses. An investigator must avoid assigning blame; to do so would be counterproductive to the investigation and might hamper future investigations.

Accident investigations should be conducted as soon as possible after the incident. When injuries are involved, the investigation usually begins after medical assistance has been provided and the injured employee has been transported to a medical facility. However, if an investigation can be started without hampering medical assistance, then it should begin immediately.

Investigation steps

The first step in conducting an accident investigation is to prevent disruption of the scene and to protect evidence. Use barricade tape or assign a person to keep out unnecessary personnel who may disrupt the scene. This does not include emergency responders, law enforcement or your insurer’s claims department who you should work cooperatively with.

The second step is to locate witnesses and take their statements. Witnesses must be interviewed individually and should be asked to refrain from discussing the accident with others until an investigator can take a written or recorded statement. It is important that witnesses be told the reason for the interview is to determine facts and find the accident cause, not to find scapegoats or place blame.

The third step is to inspect, document and make a sketch of the accident scene.

  • The scene of an accident may be visited a number of times after the accident occurs as new information or questions arise.
  • It is important to make initial observations, take digital photographs, and draw sketches as soon as possible after an accident since witnesses can forget important facts. The investigator’s notes should be clear and concise and reflect only the facts brought out in the investigation, along with statements offered by witnesses. The investigator should not form opinions or guess as to accident causes.
  • Secure, label or tag evidence that is removed from the accident area so that it does not become damaged, contaminated or lost.
  • An evidence log, which must remain with the accident investigation file, should list all evidence that has been secured, sketched or photographed. The evidence log should state each type of evidence, how it was secured, where it is located, and who is in control of it. When equipment or machinery is involved in an accident, it is important to record the exact type, make, model number, serial number and other features.

The final step is to develop the accident investigation report. The report will contain the facts, observations and corrective actions necessary to prevent future accident occurrences. The report should identify who is responsible for each corrective action and the date the action will be completed. Accident investigations provide valuable information that should be communicated to all company employees and can be used as part of training to underscore the importance of following company safety rules and safe procedures.


This material is provided for informational purposes only and does not provide any coverage or guarantee loss prevention. The examples in this material are provided as hypothetical and for illustration purposes only. The Hanover Insurance Company and its affiliates and subsidiaries (“The Hanover”) specifically disclaim any warranty or representation that acceptance of any recommendations contained herein will make any premises, or operation safe or in compliance with any law or regulation. By providing this information to you. The Hanover does not assume (and specifically disclaims) any duty, undertaking or responsibility to you. The decision to accept or implement any recommendation(s) or advice contained in this material must be made by you.

LC APR 2019 12-169
171-0894 (1/14)