This document provides information on accident investigation and prevention. It begins with an introduction of Yawar Hassan Khan as a certified HSE professional. It then defines an accident and common accident types. The document discusses theories on accident causation and emphasizes a systems approach. It outlines responsibilities and procedures for accident investigation including securing the scene, interviews, analyzing the sequence of events and causes. Recommendations are made to correct hazardous conditions. The goal is prevention, not fault-finding. Interview techniques and analyzing accident factors, hazardous conditions, unsafe behaviors and system weaknesses are covered. The report format includes background, description, findings, recommendations and summary. Feedback is welcomed.