OSHA has some really nice resources to aid in creating procedures for responding to an accident. Below is a link to the page. Each facility should develop procedures to investigate accidents. It should be noted, the safety of people come first. If someone is injured, the Emergency Action Plan (EAP) should be followed to aid any victims. Once the emergency is resolved, this is when an accident investigation takes place. Sample accident investigation procedures can be found in the Policies/Procedures section.