FIRE INVESTIGATION : DETERMINING HOW THE FIRE STARTED
Once it has been determined where the fire started, known as the Specific Point of Origin, utmost care is taken to ensure that this site is not disturbed until it has been comprehensively documented and photographed. Every single item – located both on the soil surface and below it – is recorded and eliminated as the possible cause of the fire.
There are approximately 18 recognised causes of wildfires, each of which is considered as the possible ignition source once the specific point of origin has been determined.
These are:
- Lightning: A common occurrence in specific areas
- Falling rocks: Some areas have rocks that cause sparks when struck against each other
- Self combustion
- Campfires (social / cooking / heating)
- Cigarettes
- Intended burning activities (prescribed operations)
- Incendiary (arson)
- Equipment use (chainsaws, vehicles overheating, etc.)
- Railroad (Steam trains, railway works)
- Children playing with matches
- Power lines (including trees falling against the power lines)
- Fireworks (mainly at specific times of the year, and in specific areas.)
- Cutting, welding and grinding: Normally alongside roads
- Firearms use: Usually at shooting ranges
- Blasting: Restricted to mining and development sites
- Structures (chimneys)
- Glass refraction/magnification
- Flare stack/pit fires (burning rubbish)
Working through the list, it is often easy to eliminate certain causes.
Some obvious examples include “Railroad” if there is no railroad in the vicinity, and “Glass refraction” if the fire started at 3 am.
Other causes are considered in conjunction with environmental conditions at the time of the ignition, such as temperature, relative humidity, and wind strength.
