A falling power pole on the property of an 82-year-old woman sparked the Perth Hills firestorm that destroyed 55 dwellings but an energy regulator says she is unlikely to be penalised.
As inspectors confirmed on Wednesday a private power pole caused Sunday's blaze, the question of responsibility for private power poles remains under a cloud, with EnergySafety saying there is no ongoing requirement for infrastructure to be inspected after it is installed.
The pole was on the property of 82-year-old Noreen Campbell, who has lived in the hills for 40 years.
"Mum was pretty upset by the fire, and she evacuated, and then it kept getting worse and worse and worse," Ms Campbell's son Stewart told Fairfax radio.
While local authority advice says it is the homeowner's responsibility to have private power lines inspected and maintained, EnergySafety executive director Ken Bowron said it was unlikely Ms Campbell would face any penalty from them.
"We've got our investigations to continue so I don't want to pre-empt where any of those might be going, but the requirement is that electrical infrastructure is tested and inspected when it's first put in service and there is no ongoing requirement from that," Mr Bowron said.
With no responsibility on electricity provider Western Power, the state government said it would cost millions of dollars if the onus for inspection of private power poles fell to the government.
"The [energy] minister needs to look at what's possible, look at how we can try and improve the safety so we don't have events like this occur again," acting Premier Kim Hames said.
Mr Bowron said it was not illegal to not maintain electrical infrastructure but Ms Campbell's family said the elderly resident would probably still seek legal advice.
EnergySafety revealed a short circuit sparked the catastrophic fire, with more than $13 million in damage already reported by insurers.
"The insulation on the consumer wiring leaving the main switchboard that was attached to the pole was damaged as the pole fell," Mr Bowron said.
"This caused a short circuit in the wiring, and the resulting sparks and hot metal ignited the fire."
The power pole will be inspected by a timber expert on Thursday.
Residents were allowed to return to their properties on Wednesday evening.
Authorities have also warned that anyone caught looting will be charged after reports of properties within the "hot zone" near Parkerville and Stoneville possibly being targeted by thieves.
Stoneville resident Greg Jones, who stayed to fight the fires, told ABC radio he saw a man run past with a washing basket full of items.
WA Police Commissioner Karl O'Callaghan said he had no confirmation of looting, but residents should report suspicions.
More than $100,000 has been donated by the public to the disaster fund.
