Was Heinrich wrong? or simply misunderstood? The recent emphasis on Significant Incident and Fatality (SIF) Precursors have challenged safety professionals to rethink long held assumptions of the causes of workplace accidents. This session will report on the findings of a recent study of SIF precursors in high risk workplace incidents. Experienced safety professionals can benefit from rethinking the incident investigation process to determine accident causation and corrective actions in a more effective way.