Incident investigation

Finding out why an injury, near miss or dangerous event happened at work, so you can fix the cause and meet your reporting duties.

Also called: accident investigation, workplace incident report, near miss investigation

What incident investigation means

An incident investigation is the process of finding out what happened, why it happened and what will stop it happening again after an injury, a near miss or a dangerous event at work. It looks for causes in the work itself (equipment, layout, procedures, training, supervision, staffing) rather than just someone to blame.

Investigating is separate from, but connected to, reporting. Serious injuries and some dangerous events must be reported to your provincial safety regulator, and injuries that need medical care or cause lost time usually have to be reported to your workers' compensation board within a set time. A good investigation helps you fill in those reports accurately.

Near misses matter as much as injuries. A box that falls from a shelf and misses someone has the same cause as the one that hits them. Investigating near misses is one of the cheapest ways to prevent injuries.

How it works

First, look after the person and the scene. Give first aid or call for help, then make the area safe. For a serious injury, do not disturb the scene beyond what is needed to help people and prevent more harm until you have checked your province's rules; some serious incidents must be left as they are until an inspector allows otherwise. Make the required reports.

Then gather facts quickly while memories are fresh. Take photos, note the time, the equipment involved and the conditions (lighting, floor, weather). Talk to the injured worker, when they are able, and to witnesses, one at a time. Ask open questions: what were you doing, what happened next, has this happened before?

Look for root causes. Ask 'why' several times. A worker slipped; why? The floor was wet; why? The cooler leaks; why? It was reported last month and not fixed. The fix is the cooler and the reporting system, not just a reminder to be careful. Involve your committee member or health and safety representative where you have one.

Write it up and act. A short report should cover what happened, the causes you found, the corrective actions, who is responsible for each and by when. Follow up to confirm the fixes are done and working. Keep the report with your safety records. Common mistakes: stopping at 'worker error', not investigating near misses, and writing recommendations that are never completed.

Incident investigation by province

Every province expects employers to investigate and report serious incidents, but the definitions of a serious incident, the reporting deadlines and who must be told differ.

Where the work is done	The rule
British Columbia	Start a preliminary investigation right away and complete it, with its report, within 48 hours of the incident. Then do a full investigation into the causes and corrective actions, and submit the report to WorkSafeBC within 30 days of the incident. Share the full report with your joint committee or worker representative, or post it if you have neither.
Ontario	For a critical injury or death, immediately notify the ministry's Health and Safety Contact Centre, your joint health and safety committee or representative, and the union if there is one. Do not disturb the scene, and send a written report within 48 hours. Report a work-related injury to the WSIB within 3 business days of learning about it, online through WSIB online services.

We have not yet confirmed the reporting rules and deadlines in the other provinces and territories. Check with your provincial safety regulator and your workers' compensation board.

Example: A slip in a restaurant kitchen

Carlos owns a restaurant in Charlottetown with 12 staff. A dishwasher slips near the walk-in cooler and sprains her wrist. She goes to a clinic and misses two shifts.

Carlos reports the injury to WCB PEI and then looks into the cause with his health and safety representative. They find water pooling from a cooler door seal that a cook had mentioned weeks earlier, but nobody wrote it down. Carlos has the seal replaced, puts an anti-slip mat at the door, and starts a simple maintenance request sheet on the kitchen wall that he checks each morning. He files the report with his safety records.

Free WCB calculators

Staffkin's free WCB claim cost calculator estimates what a lost-time injury can cost your business, which helps when deciding what fixes are worth making.

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Questions about incident investigation

Do I need to investigate a near miss?

It is good practice and often expected. A near miss has the same causes as an injury, so fixing it prevents the next one.

Who should investigate a workplace incident?

Someone who understands the work, ideally with a worker member of your committee or your health and safety representative. For serious incidents, consider outside help.

Is the incident report the same as the WCB report?

No. The WCB report is the claim form the board needs. Your incident investigation report is your own record of causes and fixes.

Official sources

General information for Canadian employers, not legal advice. Rules differ by province and territory and change over time, so check with your provincial employment standards office (or the federal Labour Program if you are federally regulated) before you rely on it. See employment standards by province.

Checked against official sources on 5 November 2026.