Circumstances leading up to entrapment

Table One summarises the principal cause of the entrapment. A sudden and unexpected intensification of the fire, usually due to a wind change, is reported in many cases. Often there is very little warning before the crew is overrun, leaving no time to escape. In some cases the burnover occurs so suddenly there is no time even to position the vehicle, and the burnover must be ridden out in whatever location and orientation the vehicle is in.

Table 1. Principle cause of Burnover in 37 incidents since 1980

	Australia	Overseas	Total
Sudden change in fire behaviour Engine failed due to severe conditions Underestimation of existing fire behaviour Other mechanical failure Vehicle became stuck or bogged Unknown	10 4 4 1	5 4 1 1 2 5	15 8 5 2 2 5

In 1980, near Waterfall, Headquarters 81 was trapped by a finger of fire coming out of a gully in a "sudden blowup", with the loss of all 5 crew. The survivors of the Carey Gully Tanker, lost on Ash Wednesday in 1983, reported "3 seconds warning before a fireball hit". The crew of the Echunga Tanker reported that "20 foot high flames came out of nowhere" when they were also caught elsewhere on the same day.

Linda Engine 3 was protecting a house from an approaching brushfire when "a sudden increase in the wind" resulted in 125 ft high flames. At the 1989 Eagle fire, Engines 2387,4474 and 2379, with most of their crew dismounted to battle a spotfire, were suddenly overun by a fire whirl generated by the mainfire. This whirlwind crossed the intervening freeway and with such speed and ferocity that one firefighter was unable to climb into his vehicle despite the fact that he was already holding the doorhandle when the incident occurred. Several other crew were bowled over and burned, and only one was able to deploy a fire shelter.

Kuna Engine 620 was already disabled on the fireground at the 1995 Point fire, when a windshift caused a sudden intensification of the fire, overrunning the truck and killing its 2 crew. Engine 97 was patrolling a backburn at the 1996 Fayette fire when "the wind increased’’ causing flames to impinge directly on the truck. The engine stalled, despite repeated attempts to restart, forcing the crew to bailout and leave the truck to be consumed by fire. Intensification of the fire, which travelled "over 600 feet in 30 seconds" as it ran uphill out of a bowl, contributed to burnover of the 3 appliances in the California’s "Calabassas Incident" in 1996.

Three Bulldozers and a utility constructing a break were destroyed at the Logan fire in 1997 when the fire "made a rapid run at them, cutting off their escape route", the crews were lifted out by a helicopter which was fortuitously overhead at the time. Engine 3473, patrolling a back burn at the same fire, survived being overun by fire when changing conditions produced spotting.

The deaths of 2 highly experienced firefighters, mopping up on Scotsman’s Hill in 1997 followed a hot windshift in which the "fire moved hundreds of metres in seconds". The loss of the Wingello Tanker, with one death and seven injuries, followed "an uncharacteristic wind change of uncharacteristic strength" at a backburn.

The survivors of the 1998 Linton fire, in which the Geelong West Tanker was destroyed with the loss of all 5 crew, reported a sudden flare up on a quiet fire following a windshift, "within about 2 seconds, we were fully engulfed with flames coming right over the cabin, the wind was horrific".

Conclusion :
In almost every case, engine burnovers follow sudden and severe intensifications of fire, usually following a windshift. Witnesses and survivors have repeatedly described fires that flare up or travel with almost unbelievable speed., leaving only seconds to escape or take cover.