In this post we share the importance of accident investigation, how to talk to witnesses, what questions to ask when evaluating an accident scene, how to determine causal factors, and how to identify corrective actions. You may download the complete training resource on accident investigation

By the end of this blog post, you will be able to:

• Understand your role in the investigation process
• Gather facts
• Talk to witnesses
• Determine causal factors
• Identify corrective actions

Why Investigate Accidents?

The overall goal of accident investigation is to determine the causal factors and root cause(s) of the accident. An accident investigation is not intended to place blame on anyone. Instead, it is intended to look at procedures, training, equipment, tools, and possible deficiencies in the systems of our workplace.

• Once an investigation has found these root causes, or causal factors, corrective actions should be implemented to fix or repair the system deficiencies.
• When the corrective actions are implemented, they will prevent the accident or a similar accident from happening again.
• Another reason to investigate an accident is to document what happened and how the employee was injured. These documents are used for workers’ compensation claims and as an educational tool to help prevent a similar accident.
• The Occupational Safety and Health Administration (OSHA) also requires documentation. Information must also be entered on the OSHA 300 Log. These documents must be available for OSHA if the agency inspects your workplace.

What OSHA Wants to Know

OSHA wants to know about the accidents that happen in your workplace.

• If an accident results in the death of one or more employees, OSHA wants to be notified by phone or in person within 8 hours.
• If a single event results in the inpatient hospitalization, amputation, or eye loss of one or more employees, OSHA wants to be notified within 24 hours.
• Other injuries requiring treatment beyond first aid must be documented and the documents must be kept at the facility for OSHA to inspect or request copies. OSHA requires employers to keep a record of the details of each injury on an incident report form 301 or equivalent. Your accident investigation, along with an insurance or workers’ compensation form, will meet OSHA’s requirements for documentation.
• OSHA also requires employers to record injury information on the OSHA 300 Log. This log lists all the recordable injuries that have occurred at your workplace.
• Each year, OSHA requires employers to post the OSHA 300A form, which is a summary of the 300 Log from February 1 through April 30, for all employees to see how many injuries occurred in the previous year and what type of injuries they were.

Your Key Role in Accident Investigations

You have a key role in accident investigations, even if you are not part of the investigation team.

• Report any accident or near-miss immediately to your supervisor, no matter how small.
• Cooperate with investigators.
• As a witness to the accident, describe only what you observed. Do not try to guess or assume what people involved in the accident were doing or attempting to do. Describe exactly what you observed just before the accident, during the accident, and right after the accident. The accident investigation team will lead you with their questions.
• Employees have knowledge about normal operating practices that investigators will need to know about. Your knowledge of equipment, personal protective equipment, tools, and normal work conditions will help investigators determine what was different in the situation in which the accident occurred and will help investigators find causal factors.
• Employees also provide the best ideas for corrective actions that can help prevent a similar accident or near-miss from happening again. Give your ideas to the investigators so they can help make your workplace a safer place for everyone.

Accident Investigation Team

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

• Employees trained to investigate accidents may bring a perspective that managers may not have. Employees from outside the accident area may know the right questions to ask and those in the accident area may be witnesses or answer questions about normal area operations.
• Safety committee members also make good investigation team members because they have a bigger picture of the safety issues.
• The supervisor where the accident occurred should also be involved in the investigation. He or she will provide insight into normal operating procedures, employee training, and other issues.
• The safety manager is important because he or she has a keen sense of safety issues and potential hazards and may be required to write the final report.
• The production manager, or the supervisor’s boss, should also be involved, especially for the more serious injuries.
• When the plant manager is involved, employees understand that safety is taken seriously by upper management.

Investigator’s Qualifications

The investigation team must be trained in order to ensure a complete and effective investigation.

• As a member of the investigation team, you must understand the importance of your role. You play an important part in preventing future, similar accidents from occurring.
• As a team member, you must know that you have a certain level of authority which includes closing off the accident scene, asking questions, and making recommendations. You must also understand that you are accountable to management and other employees for conducting a thorough investigation, finding root causes, and recommending corrective actions.
• You must have the skills to evaluate the accident scene. You must be able to identify contributing causal factors, question a witness, and be able to put together the sequence of events.
• You must be able to clearly communicate, both verbally and in writing, what you have discovered during the investigation.

Need to Investigate all Accidents

Many workplaces only investigate major accidents that result in serious injuries.

However it is important to investigate all types of accidents, including those that involve:

• Workplace fatalities.
• Lost time from the job or days away from work when someone is injured seriously enough that he or she cannot return to work for a period of time to do any kind of work.
• Restricted ability to work when the injured employee is not able to return to his or her regular job and is placed in a temporary job where he or she can still work without exceeding the doctor’s work restriction.
• Medical treatment when the injured employee is treated by a doctor or a nurse or sent to a clinic or hospital to be evaluated but the worker is still able to return to his or her regular job without restrictions.
• When a worker is slightly injured and requires only first-aid treatment.
• Near-miss incidents, which are those “that was close” moments. Although no injury occurred, someone could be injured doing that same task or in that same situation next time. Investigating near-miss incidents prevents serious injuries from occurring.

OSHA strongly recommends employers to investigate all incidents which a person was hurt as well as close calls in which a person might have been hurt.

When to Investigate

Ideally, the investigation should begin immediately. The investigation team should be assembled, and the process should begin as soon as possible after the incident occurs.

• Interview witnesses as soon as possible. The memories of the injured employee and witnesses are affected by time. They may elaborate on the story or forget important details if they are not questioned immediately.
• Assess the scene before clues are moved. Potential causal factors might be removed. For example, the equipment involved may be moved, the slippery floor cleaned up, the broken ladder repaired. Investigators want to arrive at the scene before anything is changed.
• Finish and write up the investigation quickly, while the details are still fresh in your mind. Waiting a day or two is just not acceptable. By then, you have lost important information, and the investigation will not be complete. Recommendations from the investigation may not be valid because they are based on inaccurate information.

Investigating like the Police

A good investigation of a workplace accident resembles a police investigation of a crime.

• Check the scene before anything has been moved or changed.
• Assemble any evidence you can find.
• Interview witnesses while the experience is still fresh in their minds.
• There is one big difference between a workplace accident investigation and a police crime investigation. You are not looking for a criminal and you are not trying to place the blame for the accident on anyone.
• You are trying to find out what happened, why it happened, and how you can prevent another similar accident from occurring.

What to Do When Accident Occurs

Employees are responsible for immediately reporting all injuries, nearmiss incidents, and facility/product-damaging accidents.

• Supervisors are responsible for ensuring all injured personnel receive proper medical treatment.
• The incident scene should be left intact until the investigation team arrives unless something presents an immediate danger to other personnel.
• The supervisor should contact the incident investigation team.
• The injured employee should complete the employee account of the incident form if he or she is able to do so.

Beginning the Investigation

Get your accident investigation kit and contact members of the investigation team.

• Once the team has gathered at the scene, decide who will be the team leader.
• Step back from the scene to look at the big picture. Look for things that are unusual or out of the ordinary.
• Record your initial observations. Try not to record what you think may have happened; just record what you see.
• Take pictures or a video.

The Investigation Kit

The essential elements of an investigation kit include:

• A camera to take pictures that can be used as evidence or to help supplement the report.
• Report forms to help make sure details are not overlooked while conducting the investigation.
• Barricade tape to block off the accident scene until the investigation is complete.
• A flashlight to look for those hidden details.
• A tape measure to record distances and heights.
• A tape recorder to record witness statements or investigators’ observations.
• Work gloves to move equipment or debris.

Questions that Need Answers

The investigation team should approach the accident scene like detectives and try to answer these questions.

• What happened?
• When did it happen?
• Where did it happen?
• Who was involved?
• How did it happen?
• Why did it happen?
• How can we keep it from happening again?

Fact Gathering

• Record the employee’s name, job title, and department. Also record the name of the employee’s immediate supervisor. Other helpful information may be how long the employee has worked for the company and how long the employee has been assigned to the job where injured.
• Record the name of employees that were working nearby that may have witnessed the incident. These employees may not have actually seen the incident occur, but may be able to describe what was happening before the incident, what they heard during the incident, and what transpired after the incident.
• On what day and at what time did the incident occur? Was this a Monday morning incident that may have been an injury left over from the weekend? Did the incident occur just before break time—the employee could have been in a hurry? Was the employee coming back from vacation or looking forward to an upcoming vacation? Consider date and time when evaluating contributing causes.
• Was the injured employee working his or her normal shift? Was the employee working overtime or a double shift?
• Describe the general location where the incident occurred and be specific. For example, north side of production line #1 or SW corner of maintenance shop.
• Describe the specific location. Was the employee on a ladder or work platform? Did the employee crawl under a machine or conveyor? Was the employee in a forklift or confined space? What was the employee working near?
• Was the injured/involved employee doing his or her normal job duties when the incident occurred? Did the employee have adequate training to perform this particular job?
• Record in detail the type of injury that occurred. Was it a cut, bruise, apparent broken bone, muscle strain, crush, electrical shock, burn, scrape, amputation, or death? Then record exactly the body part where the employee was injured (include if it was on the left or right side of the body)—eye, face, shoulder, wrist, middle finger, abdomen, groin, thigh, ankle, or big toe.
• Describe the general location where the incident occurred and be specific. For example, north side of production line #1 or SW corner of maintenance shop.
• Describe the specific location. Was the employee on a ladder or work platform? Did the employee crawl under a machine or conveyor? Was the employee in a forklift or confined space? What was the employee working near?
• Was the injured/involved employee doing his or her normal job duties when the incident occurred? Did the employee have adequate training to perform this particular job?
• Record in detail the type of injury that occurred. Was it a cut, bruise, apparent broken bone, muscle strain, crush, electrical shock, burn, scrape, amputation, or death? Then record exactly the body part where the employee was injured (include if it was on the left or right side of the body)—eye, face, shoulder, wrist, middle finger, abdomen, groin, thigh, ankle, or big toe.

Interviewing Witnesses

Witnesses should be interviewed one at a time right after the incident. Talk to witnesses at the scene of the accident so they can point out or show what they are talking about. Do not interview groups of employees together because they might confuse what they saw with what another witness said he or she saw.

• Convey your sincere concern for the safety of employees at your company, and let them know that you are trying to find ways to fix the cause of this accident. Avoid using domineering or patronizing mannerisms or speech because the interviewee will probably not respond well to that kind of attitude.
• Encourage the witness to describe the accident in his or her own words.
• Discuss what happened leading up to the accident, during the accident, and after the accident.
• Use open-ended questions. Do not interrupt the interviewee. Take detailed notes.

Sequence of Events

Based on the details learned, witness and injured employee statements, you should now be able to determine the sequence of activities involved in the incident.

• Start by describing the events that led up to the incident. Workers involved in the incident could have been walking, running, bending over, squatting, climbing, operating a forklift, pushing a broom, turning a valve, or pounding a hammer. If materials were being handled, record how heavy or bulky they were. Was material handling equipment such as a forklift, pallet jack, or hand truck being used?
• Next, describe the events of the incident. Some common language used to describe what happened to the injured employee includes: struck by an object, struck against an object, slip and trip, fall to same level or from a height, caught in/on/between, or inhalation of chemicals.
• Finally, describe events that happened immediately after the incident. What did the injured employee do: grab a knee, start limping, hold his/her arm, complain about back pain, or put a hand over the cut? Record how other nearby employees and witnesses responded to the scene. Did they call for help, administer first aid, etc.?
• The investigation team may even consider drawing a chart to show, in a simple and effective manner, the sequence of activities related to the incident

Incident Description

The incident should be described on the report in such detail that any reader can clearly picture what happened. For example: The injured employee was walking east down the main production aisle, staying to the north side of the aisle, in Building #2. He was carrying two boxes of maintenance supplies with a combined weight of 35 pounds; however, the boxes did come up to his chin and limited his field of vision. The employee did not see the 6-foot, 1/2-inch-diameter piece of conduit that was lying on the floor and protruding 18 inches into the aisle right next to the newly installed U-Make-It production machine. The injured employee stepped on the conduit with his left foot, which then rolled forward.

• Body parts: The employee fell onto his left side and did not have time to break his fall, so his left elbow squarely struck the ground. He dropped the boxes on impact.
• Motions after the incident: The employee rolled to his back, sat up, and held his left elbow in his right hand. He sat in this position for about a minute before being helped to his feet.

Causal Factors

• There are almost always multiple causes that contribute to an accident. Try not to settle on a single cause theory, because there are usually multiple contributing factors.
• Try to identify all of the underlying causes or contributing factors. In each event of the sequence of events, attempt to find potential contributing causal factors. In addition to obvious causes, such as a trip hazard, also consider possible causes such as: inadequate lighting, injured worker was carrying a large object that blocked his or her forward vision, the trip hazard was left by a maintenance person that did not pick up after his task was complete.
• Once the list of potential causes or contributing factors has been compiled, try to determine the primary cause, or the cause that appears to have contributed the most to the accident. This is the cause that, if removed, would probably have prevented the accident.
• Other causes will be considered as secondary potential causes. All causes should be investigated for corrective actions; however, the primary cause should be the focus of corrective actions.

Corrective Action

• Immediate corrective actions are those done right after the investigation is complete. These will remove a danger and prevent a repeat of the accident until formal, or long-term, corrective actions can be completed. Examples include: remove trip hazards, clean up slip hazards, take unsafe equipment out of service.

• Once the investigation team has compiled the investigation report, they can make a number of recommendations to management. These might include:

• Employee training on safe work practices
• Preventive maintenance activities that keep equipment in good
• operating condition
• Evaluation of job procedures with a recommendation for changes
• Conducting a job hazard assessment to evaluate the task for any
• other hazards and then train employees on these hazards
• Engineering changes that make the task safer or administrative
• changes that might include changing the way the task is performed

Complete Report

One member of the investigation team is selected by the team to write up the report with the investigation recommendations.

• All members of the investigation team review the report and sign it if they are in agreement.
• The report is also signed by the injured employee to acknowledge that he or she has read and understands the investigation team’s findings.
• The report is forwarded to management so it can be placed in the worker’s file as well as for use in handling any workers’ compensation claim.

Key Point to Remember

Accident investigations prevent other accidents

• Investigate accidents immediately
• Gather all the facts
• Interview witnesses one at a time
• Record detailed description
• Determine causal factors
• Conduct corrective actions

Download our complete training resources on accident investigation for your safety training