[1]: 7–8  Approximately 386 hectares (1,000 acres) of uncleared land and pasture—the majority on private property—were burned during the 21-day duration of the fire.

The source of ignition was determined by both the DFES and Energy Safety to have been a fallen power pole, which ignited extremely dry vegetation at approximately 11:00 AWST (UTC+8) during a period of easterly winds gusting up to moderate gale force and temperatures in excess of 40 °C (104 °F).

[2][6] A considerable quantity of property in Stoneville was destroyed following a wind change that brought fresh breezes from the south west to the fire ground, just prior to 15:00 AWST.

Helena, Parkerville, and Stoneville suburbs of Mundaring Shire there are a mixture of large properties with stands of open woodland and pastures, and standard residential blocks with trees in a close vicinity to houses.

[1]: 7–8  The majority of the area eventually burned was within a broad valley sloping gently upward, west to east.