An electrical fault caused a massive bushfire that killed 121 people on February 7 last year, counsel assisting the Victorian bushfires royal commission has found.
In his submission to the commission, Jack Rush, QC, said at 11.45am on February 7, an electrical incident was reported at a Kilmore East power pole.
At 11.47am, smoke was sighted in the area and the first firefighters on the scene noticed a conductor hanging down, Mr Rush told the commission.
The faulty conductor arced, igniting the vegetation, Mr Rush said.
"We would submit that the evidence in relation to this is strong: conductor break, arcing event, fire ignition," Mr Rush said.
Police investigation under way
The commission hearing into the causes of the fire are continuing.
Mr Rush urged the commissioners not to refrain from making findings on the electrical causes of the fire because police were still investigating, or because of the pending class action.
"When the commissioners see good evidence, they should act on it," he said.
But Allan Myers, QC, for the State of Victoria, disagreed.
He said the commissioners ought to be held back by police investigations.
"The evidence is that the police are investigating," Mr Myers said.
Extreme weather conditions
Meanwhile, Mr Rush said the extreme weather conditions on February 7 did not justify the failure to predict fire behaviour and lack of preparedness by fire authorities on the day.
Mr Myers also disagreed with this.
"We reject unequivocally that suggestion... that the planning was insufficient, given the circumstances that were envisaged because of the weather predictions and the dryness of the state."
Mr Myers said it was accepted that the broken conductor sparked the Kilmore East blaze.
Lawyer for electricity company, SP AusNet, Jonathan Beach, QC, said while it had not conceded the broken conductor was the cause, the commissioners could conclude that it was.

