A contractor for utility company Western Power and a private property owner have been found liable for a bushfire that destroyed dozens of homes in the Perth suburb of Parkerville, the West Australian Supreme Court has ruled.

Key points: The bushfire was caused when a power pole affected by termites and rot collapsed

The bushfire was caused when a power pole affected by termites and rot collapsed A judge found duties of care were breached, but cleared Western Power of blame

A judge found duties of care were breached, but cleared Western Power of blame The class action involved 189 residents and property owners

The massive bushfire in January 2014 was sparked by a collapsed power pole on a property owned by Noreen Campbell, who was being sued for damages, along with Western Power and contractor Ventia Utility Services, formerly known as Thiess.

A report found termites and rot caused the collapse of the pole, leading to the fire which destroyed 57 homes as well as outbuildings and vehicles.

No lives were lost, but an earlier hearing heard the "impact was terrible".

But Justice Rene Le Miere cleared Western Power of blame in the class action, which involved 189 residents and property owners.

Duty of care breached: judge

Justice Le Miere found both Thiess and Mrs Campbell were each liable to the plaintiffs for negligence and nuisance.

He said Thiess breached a duty of care it owed the plaintiffs by failing to inspect the power pole properly.

Justice Le Miere dismissed claims against Western Power. ( ABC News: Hayley Roman )

"Thiess breached the duty of care it owed to the plaintiffs by failing to adequately train and supervise the line crew, and by failing to exercise due care and skill in inspecting the jarrah pole in accordance to its contractual obligations and industry standards," he said.

"Thiess participated in the creation of a nuisance by failing to inspect the jarrah pole properly. As a result of which the pole remained in service when it was unsafe and unserviceable, and constituted a potential nuisance."

He also found Mrs Campbell breached a duty of care to maintain the pole by failing to make any inspection.

Western Power claim dismissed

Justice Le Miere found Thiess liable for 70 per cent of the plaintiffs' damages and Ms Campbell liable for 30 per cent.

He dismissed claims against Western Power, arguing Thiess carried out the work as an independent contractor, not a Western Power agent.

"That duty was non-delegable, and Western Power discharged that duty by taking steps to engage Thiess to carry out the work."

A total of 189 residents and property owners joined the class action. ( Supplied: Department of Fire and Emergency Services )

Western Power said the trial had been vital in helping define that the maintenance of privately-owned power poles was the responsibility of land owners.

In a statement, the utility said it appreciated how difficult the trial had been, particularly for those who gave evidence.

It said the findings highlighted the need for owners of private power poles to have a regular inspection program in place.

The residents' lawyer, Lachlan Armstrong QC, told the court earlier the electricity pole was in a "deplorable" condition due to rot and termite damage, adding that a "modest gust of wind" was enough to cause it to fall.

Damages into the tens of millions

Lead plaintiffs Garry and Sandra Elwood, who lost their home in Stoneville, were relieved with the outcome.

"Not just for us but for our next-door neighbours," he said.

"It'll give us some closure … it's not just the houses that were lost, there's a whole community out there that've been suffering over the last five years.

Lead plaintiffs Sandra and Garry Elwood said they were relieved at the outcome. ( ABC News: David Weber )

"There's a lot of things behind the insurance companies that people don't see. We've had a lot of ups and downs over this last five years, not only financially but also emotionally."

Mr and Mrs Elwood's claim acted as a test case and the judgment ruled they were entitled to damages of just over $780,000.

The final total is expected to be in the tens of millions, though the litigants said they would not seek any funds beyond Ms Campbell's insurance coverage.

The figures, plus costs of counsel, and who was to pay those costs, were to be determined at a later stage.

Mr Elwood said the class action was not about the money.

"It's about being able to go home, knowing that you're going to be safe," he said.

"Personally I was a little bit disappointed that Western Power escaped that liability.

"At the moment there is still poles, literally thousands of poles, private poles that have never ever been inspected."

Plaintiff Sandra Elwood said she never placed blame on Noreen Campbell for the blaze. ( Courtesy of Department of Fire and Emergency Services )

Mrs Elwood said she was very happy with the outcome and she and others in the group had never blamed Mrs Campbell.

"I just want to see our friends and family move on," she said.

Ms Campbell was brought into the case by Western Power and Thiess, and the Slater & Gordon clients had to cross claim.

"I feel sorry for Ms Campbell, and her son" Mr Elwood said.

"We've had a hard road and I can imagine her road was just as hard."

Outside court Ms Campbell made only a brief comment.

"I don't know anything about the law so it's best to say nothing," she said.

"It's been an education to say the least. And there's been stress."

'Entirely avoidable catastrophe': lawyer

Slater & Gordon represented the 189 litigants who lost property in the 2014 blaze.

Practice group leader Rory Walsh said all his clients had fought hard to achieve today's outcome.

"This was an entirely avoidable catastrophe and two of the three defendants have now been found liable and are now required to provide compensation to our clients," he said.

"Western Power were fortunate to have avoided liability by sheeting responsibility home to its contractor, although that contractor was ultimately found to be negligent in its inspection of the pole.

Lawyers for the plaintiffs called the bushfire an 'entirely avoidable catastrophe'. ( Department of Fire and Emergency Services )

"We are closely considering His Honour's reasoning in this regard and will speak to our clients over the coming days about their options.

"We have today sought orders from the court that a mediation be convened to agree on a path forward for all our clients to be compensated in the shortest possible timeframe."

Mr Walsh said that in catastrophic events the level of under-insurance was marked and all losses were not or could not be covered.

He said he was surprised Western Power was found to be not liable.

"We think they've been extremely fortunate to escape liability," he said.

"They've escaped liability in circumstances where the court said that they discharged the duty that they owed people in relation to inspecting this pole by engaging a sub-contractor.

"That independent contractor has been found negligent by the court, the court said that its staff were not properly trained.

Slater and Gordon's Rory Walsh said Western Power had been 'extremely fortunate' to escape liability. ( Department of Fire and Emergency Services )

"And the inspection itself was carried out in a negligent way."

Mr Walsh said the implications were "immediate".

"My understanding, it is the only class action-type proceeding against a power company or its sub-contractors who have been held liable here of the modern era," he said.

"I was involved in much of the Victorian litigation arising out of the Black Saturday bushfires, those cases settled before they went to judgment.

"It's a very rare thing that we've got judgment, and it gives a lot of clarity to the legal issues arising out of this, and the responsibilities indeed, of power companies."