These were developed after studying fire line deaths. All the incidents had one or more of the following common denominators.
Most incidents happen on the smaller fires or on isolated portions of larger fires.
In some cases, tragedies occur in the mop-up stage. Flare-ups generally occur in deceptively light fuels. Fires run uphill surprisingly fast in chimneys, gullies, and on steep slopes. Some suppression tools, such as helicopters or air tankers, can adversely affect fire behaviour. The blast of air from low flying helicopters and air tankers have been known to cause flare-ups.