The Why, Who, What, When, and How of Accident Investigation


Information from: The Safety Daily Advisor Newsletter

Accident prevention often begins with accident investigation. You can’t prevent accidents if you don’t know what caused them.

Nobody wants a workplace accident. Not you. Not your insurer. Not supervisors. Not employees. Not the families of injured workers.

But when an accident does happen, it’s important to handle the investigation promptly and effectively. To do that, you need to consider the why, who, what, when, and how of accident investigation.


The main reason for any accident investigation, of course, is to determine the cause(s) of the accident so that you can identify corrective action that will prevent future similar incidents.

But there are other good reasons for investigating accidents, too. For example, to:

  • Document what happened and how the employee was injured—information that will be needed to deal with workers’ compensation claims
  • Complete the OSHA 300 injury and illness log, to fill out an OSHA 301 incident report, and to prepare OSHA Form 300A, the annual summary of injuries and illnesses
  • Prepare for an OSHA or state agency investigation prompted by the accident—for instance, following a fatality
  • Use the information revealed as an educational tool in accident prevention training sessions


A successful accident investigation team should include members from all levels of management and production. For example:

  • Employees from the work area
  • Safety committee members
  • Supervisors, especially the supervisor of the area where the accident occurred
  • The manager responsible for the employees and supervisor involved
  • Safety personnel, often including the workplace safety manager
  • A representative of upper management in the case of serious accidents
  • Legal counsel if the accident might have repercussions outside the facility or could lead to later legal action

Although not all of these people would necessarily be actively involved in carrying out the investigation, they would likely all need to be kept informed of the progress and results of the investigation.

The investigation team must be trained to ensure a competent investigation. Investigation team members should:

  • Recognize that they are accountable to management and other employees for conducting a thorough investigation
  • Have the skills to evaluate the accident scene as well as identify contributing causal factors, question witnesses, put together the sequence of events
  • Understand the particular job, equipment, etc, involved in the incident
  • Be able to communicate findings clearly


It’s essential to investigate all safety incidents, not just ones that result in serious or multiple injuries. For example, you should investigate incidents involving:

  • Lost workdays
  • Work restrictions ordered by a doctor
  • Medical treatment by a doctor or nurse
  • Minor injuries requiring only simple first aid
  • No injuries or property damage
  • Near-misses


Accident investigations should begin as soon as possible after the incident occurs and before:

  • Witnesses’ memories fade or become confused
  • Evidence is lost
  • The scene of the accident needs to be cleaned and returned to production
  • Momentum and the will to find causes is overtaken by other pressing needs


  • Survey the scene. Make sure you have a complete and accurate picture of just what happened.
  • Get the facts. Talk to those involved and those who witnessed the accident.
  • Analyze findings. Review the facts. If this was a routine situation, consider any factor that was unusual on that particular day. What went wrong? Consider all the possibilities.
  • Identify causes. Identify the immediate cause—person, place, or thing. Very often this is the easy part. List contributing factors—there may be several. List underlying causes and unpredictable factors. Discuss alternate theories if the investigating team is not in agreement.
  • Report your findings and recommendations. Tune in tomorrow when we’ll review four key elements of an incident report.
  • Follow up to ensure that recommended action is taken. Check to see that immediate changes have been made. Continue to review until all long-term preventive changes have been completed.

To learn more about how The Seltzer Group can help your business prevent and manage workplace injury, click here!

The Seltzer Group, located in Eastern Pennsylvania, specializes in developing safety, workers compensation, human resources, claims, and risk financing programs. They are a proud member of the Keystone Insurers Group and are nationally recognized for their expertise in workers compensation solutions. The Seltzer Group serves businesses and individuals locally, regionally, and on the national level.

The Why, Who, What, When, and How of Accident Investigation was last modified: August 26th, 2014 by Sarah McGorry