The Hazelwood mine fire was not just one fire—it was a complex of fires. The fire started as a series of smaller fires that ignited in the northern, eastern and south-eastern batters and floor of the Hazelwood mine on 9 February 2014.

While various suggestions were made during the course of the Inquiry that fire may have started from within the Hazelwood mine, possibly from an existing fire hole, there was no evidence to support this theory. All of the evidence before the Board led to one conclusion. The most likely cause of the Hazelwood mine fire was embers spotting from one or both of two bushfires outside the mine.

There is difficulty in determining with precision which of the external fires was responsible for the spotting of embers into the mine. On the evidence provided, spotting from the Hernes Oak fire was the more likely cause of the Hazelwood mine fire, while spotting from the Driffield fire may have also contributed. Both the Hernes Oak fire and the Driffield fire are regarded by Victoria Police as suspicious and both are the subject of ongoing investigation.

The probability of embers spotting into the Hazelwood mine was supported by clear evidence from several mine employees, contemporaneous photographs and video, expert evidence and computer simulations of likely fire behaviour on 9 February 2014.

The origin and circumstances of the Hazelwood mine fire are considered in Chapter 2.1 of the report.