fire investigation

Fire investigation, sometimes referred to as origin and cause investigation, is the analysis of fire-related incidents. After firefighters extinguish a fire, an investigation is launched to determine the origin and cause of the fire or explosion. Investigations of such incidents require a systematic approach and knowledge of basic fire science. In common with many forensic disciplines, one of the early tasks of fire investigation is often to determine whether or not a crime has been committed. The difficulty of determining whether arson has occurred arises because fire often destroys the key evidence of its origin. Many fires are caused by defective equipment, such as shorting of faulty electrical circuits. Car fires can be caused by faulty fuel lines, and spontaneous combustion is possible where organic wastes are stored. A fire investigator looks at the fire remains, and obtains information to reconstruct the sequence of events leading up to the fire. One of the challenging aspects of fire investigation is the multi-disciplinary basis of the investigator's job. As fires can be caused by or involve many ignition sources and fuels, fire investigators need to know not only the science of fire behavior, but also to have a working understanding of many different areas of study including construction, electricity, human behavior, and mechanical devices. For example, if there is a gas appliance at the origin of the fire, an investigator should know enough about appliances to either include or exclude it as a possible cause of the fire. Fire investigators sometimes work with forensic engineers, such as forensic electrical engineers when examining electrical appliances, household wiring, etc. Spoliation is the destruction or alteration of evidence through intention or ignorance. The mere act of extinguishing a fire can destroy potential evidence of arson or what is also known as an "Incendiary fire." Firefighters are educated that the stream of their fire hose or the use of a Pike Pole can destroy evidence and efforts are made to do what is required to extinguish the fire, while not destroying clues to the fires' origin. A fire investigation was once compromised by a fire fighter turning off the knobs on a gas stove in the interests of safety after a house fire was knocked down. In the following investigation the homeowners daughter was accused by her father of leaving the stove on after she left the house but there was then no way to accurately determine the position of the burner knobs on the stove. Though there were no criminal issues involved in this fire, this incident of spoliation created a lack of closure for the family and feelings of distrust and animosity within the family members.