Incident Investigation, Near Misses, Root Cause, and Corrective Action

Incident Investigation, Near Misses, Root Cause, and Corrective Action

Investigation Purpose

Incident investigation is a prevention process, not a blame exercise. It identifies what happened, why it happened, which controls failed, and what must change. The CHST exam often tests whether the investigator stops at a surface cause. For example, saying a worker fell because they were not tied off may be true, but it does not explain whether anchors were available, the task was planned, supervision was effective, training was understood, or production pressure influenced the decision.

Investigations should include injuries, illnesses, fatalities, property damage, fires, environmental releases, equipment failures, and near misses. A near miss is an unplanned event that could have caused harm under slightly different conditions. Dropped objects, trench wall movement, uncontrolled swinging loads, and almost-contact with energized parts deserve attention because they reveal weak controls before serious consequences occur.

Immediate Steps and Evidence

First provide medical care, control hazards, stabilize the area, and complete required notifications. Investigation should not interfere with rescue or emergency mitigation. Once safe, secure the scene and preserve evidence. Photos, measurements, equipment positions, permits, inspection records, training records, weather, SDSs, and witness names should be captured promptly. Damaged equipment, failed rigging, PPE, ladders, tools, and electronic records should not be repaired, discarded, or returned to service before review.

A basic sequence is:

1. Care for injured people and control immediate hazards.
2. Notify required internal and external parties.
3. Preserve the scene and evidence.
4. Collect facts through photos, documents, measurements, and interviews.
5. Build a timeline.
6. Identify immediate, contributing, and root causes.
7. Select corrective actions using the hierarchy of controls.
8. Assign owners, due dates, and verification steps.

Witness interviews should be prompt, respectful, and fact focused. Ask open questions: What did you see? What changed? What task was underway? What instructions were given? What conditions were unusual? Separate direct observations from assumptions or rumors.

Root Cause and Corrective Action

Root cause analysis looks beyond the last action before the incident. Methods such as five whys, barrier analysis, fishbone diagrams, or causal charts can help, but the tool is less important than disciplined thinking. Recommending retrain employee for every event is usually weak unless the investigation explains why training failed and why training is the right control.

Corrective actions should follow the hierarchy of controls and be specific, assigned, and verifiable. Install guardrails on the west mezzanine before work resumes is stronger than be careful. Actions should include owners, due dates, interim controls, and effectiveness checks. If a fix creates a new hazard, it must be revised.

Lessons learned should be shared with affected crews while protecting privacy and avoiding unsupported blame. Trend incident and near-miss data for recurring issues such as housekeeping, struck-by exposure, heat illness, or subcontractor coordination. Investigation is complete only when corrective actions are implemented and verified.