A comprehensive and sound investigation of an accident requires the investigator to establish the sequence of events and related factors that led to the actual accident. In establishing this order of events, the investigator needs at first to collect different types of information that describes the accident scene and its surrounding conditions as a clue to what might have led to the accident (Vincoli, 1994). The four P’s of evidence set a good foundation for determining this sequence.
Types of Information
The physical evidence gives information about the lower level of accountability such as the position and condition of equipment, machinery and environment. This information is very important in determining what might have been the previous action before the equipment or tool is, where it is after the accident. Hence, the investigator is able to determine what is absent or present (Geigle, 2007). Information about the environmental condition evaluates the possibility of its influence on the occurrence of the accident.
Information gathered through the paper evidence establishes the higher level of accountability in an accident. Information about the work instructions, organizational policies, training and procedures illuminates the possible root of an accident. Any weakness highlighted in the paper evidence has a greater responsibility in the overall sequence.
More importantly, eye or ear witnesses are precise sources of information. As such, people evidence gathered from victims, supervisors, or co-workers can narrate all that they observed or heard to help preempt the previous or consequent occurrence (Geigle, 2007).
Drawing from the common belief that pictures is worth a thousand words; the investigator should also use information from the picture evidence. The photo shots of the accident scene taken at different orientations may depict what happened before or after a given case (Geigle, 2007).
Thorough understanding of sequence of events during accidents is a key principle in the accident investigation. Before settling on any factor as the root cause of an accident, an investigator should collect all the four categories of information for the informed analysis of the casual factors.