How do I investigate a workplace incident?

Work through five steps. First, establish the sequence of events — what happened, step by step, from the facts. Second, identify the immediate causes (the unsafe conditions and actions right before it). Third, find the contributing factors behind those causes across people, environment, equipment, procedures and organisation. Fourth, use the 5 whys to drill down to the root cause — the underlying system gap. Fifth, set corrective actions mapped to the hierarchy of controls, each with a responsible person, a due date and a review date. The aim is to prevent recurrence, not to assign blame.

What is root cause analysis?

Root cause analysis looks past the immediate trigger of an incident to the underlying reason it was possible — usually a gap in a system, procedure or control rather than a single person's mistake. A common technique is the 5 whys: you ask 'why did that happen?' for each cause, repeating until you reach something you can fix at the system level. Fixing a root cause stops the same type of incident recurring, where fixing only the immediate cause often does not.

Should I blame the worker for a workplace incident?

No. Blaming the worker stops the investigation at 'human error' and misses why the work system allowed the error to happen — fatigue, unclear procedures, poor equipment, time pressure or inadequate supervision. A good investigation treats human error as a starting point, not a conclusion, and asks why a competent person could make that error in that situation. Fixing the system causes is what actually prevents recurrence; blame does not.

Do I have to investigate a workplace incident?

Investigating incidents is part of managing work health and safety risks. Under the model WHS laws a PCBU must, so far as is reasonably practicable, manage risks — which includes reviewing control measures after an incident to make sure they remain effective. Officers (such as directors) have a separate due-diligence duty under s27 to ensure the business has, and uses, appropriate processes for receiving and responding to information about incidents and hazards. Investigating, finding the root cause and acting on it is how you meet those duties.

What should I do about a notifiable incident before investigating?

If the incident is notifiable — a death, a serious injury or illness, or a dangerous incident — you must notify your WHS regulator immediately and you must not disturb the incident site until an inspector arrives or the regulator allows it, except to help an injured person, remove a serious risk, or preserve evidence. Use the Notifiable Incident Checker to confirm whether you need to notify. For serious matters, consider getting legal advice before you document findings, because investigation records can be used in proceedings.

Workplace Incident Investigation Builder

Investigate a workplace incident properly — sequence of events, contributing factors, root cause and corrective actions you can act on.

Last verified: 21 June 2026

Assemble a structured incident investigation report: sequence of events, immediate causes, contributing factors by category, the root cause via the 5 whys, and corrective actions mapped to the hierarchy of controls with owners and due dates — then print it or save it as a PDF. This is the 'now what' companion to the Notifiable Incident Checker. General good-practice methodology, not legal advice.

Investigate to prevent recurrence, not to assign blame

A good investigation finds the system causes that let the incident happen, then fixes them. If this was a notifiable incident you must preserve the site and notify your regulator first — check with the Notifiable Incident Checker. For serious matters, get advice before finalising what you document.

Incident details

Investigation referenceDate and time of incidentWhat happenedLocationPeople involvedInjuries or damage

This is (or may be) a notifiable incidentA death, serious injury or illness, or a dangerous incident. If ticked, the report records that the site must be preserved and the regulator notified.

Sequence of events

Set out what happened step by step, in order — one event per line. Stick to facts (what, not why) and use the people's accounts and any evidence.

Immediate causes

The conditions or actions immediately before the incident — the unsafe conditions and acts. One per line.

Contributing factors

Behind the immediate causes are the conditions that allowed them. Work through each category and list the factors that contributed — one per line. Most incidents have factors in several categories.

PeopleFatigue, training, experience, supervision, communication, instructions followed or understood, time pressure.Environment / workplaceLayout, lighting, noise, weather, housekeeping, access, hazards in the surrounding area.Equipment / plantTools, machinery, guarding, maintenance, suitability for the task, condition, faults.Procedures / systems of workSafe work procedures, risk assessments, permits, the procedure missing, unclear, out of date or impractical.Organisation / managementStaffing, workload, budget, competing priorities, safety culture, how risks are managed and reviewed.

Root cause — the 5 whys

Keep asking "why did that happen?" for each cause until you reach something you can fix in a system, procedure or control — not a single person's error. List each why on its own line.

Root cause(s)The underlying system gap(s) the whys point to. One per line.

Corrective actions

For each root cause and contributing factor, decide what you will change. Pick the highest hierarchy-of-controls level you reasonably can, and give every action an owner and a due date.

Action

Hierarchy of controlsResponsibleDue date

Investigator and review

InvestigatorCorrective-action review date

Opens your browser's print dialog. Choose "Save as PDF" to keep a copy or share it with your team, HSR or regulator.

Incident Investigation Report

Prepared with FairWorkMate.com.au — general information, not legal advice.

Purpose

The purpose of this investigation is to prevent recurrence — not to assign blame. Look past who made an error to why the work system allowed it to happen.

1. Incident summary

Investigation reference: —
What happened: —
Date and time: —
Location: —
People involved: —
Injuries or damage: —
Notifiable incident?: No / not yet determined

2. Sequence of events

Not yet recorded.

3. Immediate causes

Not yet recorded.

4. Contributing factors

Not yet recorded.

5. Root cause analysis (5 whys)

Not yet recorded.

Root cause(s)

Not yet recorded.

6. Corrective actions

Not yet recorded.

7. Investigator and review

Investigator: —
Corrective-action review date: —

Preserve the site and get advice for serious matters

If this is a notifiable incident (death, serious injury or illness, or a dangerous incident), you must not disturb the incident site until an inspector arrives or the regulator allows it, except to help an injured person, make the site safe or preserve evidence. Notify your WHS regulator as required, and for serious matters consider getting legal advice before documenting findings — investigation records can be used in proceedings. Check whether you need to notify with the Notifiable Incident Checker.

Notes

An investigation looks for system causes, not someone to blame. The aim is to stop the same thing happening again.
Use the 5 whys to keep asking why each cause occurred until you reach a root cause you can fix — usually a gap in a system, procedure or control, not a single person's error.
Map every corrective action to the hierarchy of controls. Higher-order controls (eliminate, substitute, isolate, engineering) are more reliable than relying on administrative controls or PPE alone.
Give every corrective action a responsible person and a due date, then review on the review date that each is done and effective.
This report is a general good-practice template, not legal advice. For serious incidents, get advice before finalising what you document.
Methodology verified as at 2026-06-21: Safe Work Australia incident-investigation guidance; ICAM contributing-factor categories; model WHS Act s27 (officer due diligence) and Part 3 (notifiable incidents).

Methodology verified as at 2026-06-21. Sources: Safe Work Australia incident-investigation guidance; ICAM contributing-factor categories; model WHS Act s27 (officer due diligence) and Part 3 (notifiable incidents).

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FairWork Mate is an independent commercial service. We are not affiliated with, endorsed by, or associated with the Fair Work Ombudsman, the Fair Work Commission, or any Australian Government agency. Content is general information and estimates only — not legal, financial, or tax advice. Always verify with the Fair Work Ombudsman (13 13 94) or a qualified professional.

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Workplace Incident Investigation Builder

Incident details

Sequence of events

Immediate causes

Contributing factors

Root cause — the 5 whys

Corrective actions

Investigator and review

Incident Investigation Report

1. Incident summary

2. Sequence of events

3. Immediate causes

4. Contributing factors

5. Root cause analysis (5 whys)

6. Corrective actions

7. Investigator and review

Notes

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