The Secret to a Successful Incident Investigation

Published: October 24, 2018

The Secret to a Successful Incident Investigation 

By: Dylan Hipple CHST, GSP

Nearly eleven workers die on the job every day, and five million are injured annually in the United States. Based on statistics, at some point it is likely that your company will have the need to conduct an incident investigation. Knowing what to do in these situations and providing a rapid response is key to a strong safety commitment and to preventing similar incidents. The main purpose of an incident investigation is to determine the causal factors or root causes and determine a plan of action to prevent future occurrence. It should never be the intent to find fault during an investigation.

Injuries affect everyone. There are multiple indirect results of an injury. The loss does not simply stop with the injured employee. Injuries cripple an entire families’ ability to earn an income, care for their dependents, and sustain their quality of life. Once an injury occurs we cannot take it back, but we can do everything in our power to ensure that future incidents are prevented. In comes the incident investigation. The investigation is the key to stopping these detrimental incidents from re-occurring.

Steps in the Process: What to do Following an Incident?

  1. Care for the injured worker – The first priority is always the care of the injured worker. Life safety will always take priority over anything else in the investigation process.
  2. Secure the area where the incident occurred – Scene preservation is necessary to collect the information needed to get an accurate representation of the area right before the incident occurred. Securing the area is usually done through the use of barricade tape.
  3. Identify and gather witnesses – It is important to identify anyone who may have witnessed the incident to get their perspective/point of view. The incident may look different from other vantage points.
  4. Interview involved worker(s) and witnesses - The interview process is vital in determining the facts surrounding the incident. Witness testimonies, as well as testimonies from workers involved, will help to re-create the mindset and stage right before and during the incident.
  5. Document the scene through photos and sketches - It is near impossible to recall every aspect of a scene strictly through memory. It is important to have photo documentation to go back and look through for context clues.
  6. Complete the investigation report to include root causes and corrective actions taken – The purpose of an incident investigation is to determine the root causes and to develop a plan of action based on the root causes to prevent future occurrences.
  7. Use the results to improve your company’s injury and illness program – If an incident investigation is completed and nothing is done with the information, what’s the point? The key to a successful safety program is using the results and determining a plan of action necessary to prevent future similar occurrences.

Do you have a documented process for investigating incidents? All successful programs have a written documented process for these situations. The following questions should be addressed in the formal written program:

  • Who is going to conduct and participate in the investigation process?
  • What types of incidents get investigated? All injuries? Property damage? Near misses?
  • What info will be collected during the investigation process?
  • How are root causes identified?
  • Who makes the determination of corrections that take place as a result of the investigation?
  • How will the completion of corrected items be tracked?

Who Should be Involved in the Investigation:

Typically, the person most suited for the investigation is the direct supervisor of the injured worker. The direct supervisor should know the most about the injured employee’s scope of work and normal job duties/functions, therefore giving them the best chance at determining causal factors. A best practice in the process would be to have a member of the safety department or investigation team assist in the investigation process. If the incident involves a fatality then senior management, engineering staff or legal counsel should also be involved.

What Type of Incident Gets Investigated?

It is ultimately the company’s decision on what type of incident should be investigated. Typically, an incident that results in a fatality, serious injury, or damage to equipment or environment should be investigated thoroughly. To obtain the best possible data to aid in predicting and preventing future incidents, it is also recommended that all recordable, first aid and near miss/close call incidents be investigated. Near misses will eventually transcend into serious injuries. If all near misses are investigated the chance for avoiding these types of incidents significantly increases.

What Information Should Be Collected?

Worker characteristics are important in the process and should be documented. Age and gender are two aspects that may help determine a root cause. Other factors include job title, experience level of the employee, job status (part time or full time), and department within the company. Training could also play a vital role in determination of causes. Was the employee trained in the task they were performing?

Injury characteristics should also be recorded. What part of the body was injured? What level of severity was the injury? The injury should be described in as much detail as possible. This information will be recalled multiple times during the process.

A narrative description and the sequence of events leading up to the incident are vital. What was the location of the incident? What was the injured employee doing prior to and leading up to the incident or near miss? Were there other people involved? Were there substances or equipment involved? Did environmental conditions play a factor? What was the temperature, noise level, lighting, and weather? Record how the injury occurred. Were there preventative measures in place to prevent these types of incidents? What happened directly after the injury or near miss occurred? These questions should all be answered and recorded on the incident investigation report.

The characteristics of the equipment involved should be recorded to include the type, brand, size, distinguishing features, condition, and any specific parts involved. Condition of the equipment often plays a key role in determining root causes during the investigation process. It is often determined that equipment was not functioning as intended or the inspection process had been overlooked.

The specific task that was performed by the injured worker when the incident occurred should also be documented. The following questions should be answered: What was the general task being completed? What specific activity occurred during the incident? What was the location and posture of the injured worker? Was this employee working alone or with others? What time of day did the incident occur? At what point in the injured worker shift did the incident occur? Was the employee directly supervised during the incident? What corrective actions have been taken short term and long term to correct this issue?

What Should be Located on Scene?

Being prepared is key to a successful investigation. Incident’s are not planned and happen when you least expect them to. That is why it is important to always be prepared to handle with a rapid response plan. One of the best solutions for a prompt response time is the implementation of an incident investigation kit. The kit should include the following:

  • Incident investigation forms
  • Witness statement forms
  • Barricade tape for securing the work area
  • LO/TO equipment to include locks and tags
  • All forms of PPE
  • Flashlight
  • Tape measure
  • A pen
  • Camera or video recorder

Conducting the Interviews

Interviews are a vital part in determining the facts surrounding an incident. Witness interviews often bring out the details that help determine root causes. During the interview process many people have the tendency to become nervous and have increased anxiety. It is your job as the interviewer to eliminate these feelings and build a good rapport with the person being interviewed. You can follow these tips to ensure a good interview:

  1. Conduct the interview in a neutral place. This location should be quiet and private. You want the interviewee to be as comfortable as possible.
  2. When asking questions ensure they are open ended so the person answering can give their version of the truth.
  3. Ensure the person being interviewed understands the purpose of the interview. It should be made clear to them that the interview is to determine the facts so that the same scenario does not happen again. It is never the purpose of an interview to find fault.
  4. Ask the person to give their version of the event. Be sure not to interrupt the person while they are recalling the incident. As they are answering, take note and record their story.
  5. If needed, ask questions to clarify any gaps in information
  6. State the information collected back to the interviewee
  7. Ask the individual, in their opinion, what could have been done differently to prevent the incident. Take into account the conditions and events that occurred prior to the incident.
  8. Thank the witness for their cooperation and finish documenting the interview.

Putting Together the Facts to Determine Root Cause(s)

As you’ve continued to read throughout this article, the main purpose of the investigation is to determine the root causes. At this point in the process all the facts have been collected and laid out in front of you. Starting from the end result of the incident, look back and start to ask “Why” to avoid incomplete and misleading conclusions. For example – John Smith broke his hand. “Why did he break his hand” because he slipped on oil. “Why did he slip on oil?” Because the forklift was leaking oil. “Why was the forklift leaking oil?” because it had not been serviced. “Why was it not serviced?” There was no maintenance schedule for the forklift. The root cause of this incident was that there was no maintenance schedule for the forklift. If needed, you could continue to drag this out further and keep asking why until there is no other question left to answer. There may be a single root cause or multiple root causes. There may also be many contributing factors that lead to an incident. Contributing factors could involve equipment, environment, people or even management’s decisions. Below are some questions that help determine these casual factors.

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/worker(s) a contributing factor? (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 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)

Closing Out the Investigation:

Wrapping up the investigation, creating a report, and following up with corrective actions will ensure that similar incidents do not occur. After the root cause has been determined, corrective actions should be implemented. It is important to come up with a system that works for you and your company to follow up with the corrections implemented. If no follow-up is conducted, you may have another comparable incident. This article gives the basic guidelines for creating a successful incident investigation program, but it may not work exactly the same way for each company or situation. It is important to tailor the investigation process to your specific needs for the most effective results.

Dylan Hipple CHST, GSP


National Safety Council – “How to Conduct and Incident Investigation”