Hundreds of people who lost homes and businesses in last October’s Blue Mountains bushfire have launched a $200 million class action against power company Endeavour Energy.

Law firm Maddens says it is a secure and low-risk way for residents to claim losses that insurance policies did not cover.

“Quite simply, the residents of this area have suffered losses that are not their fault,” Maddens senior partner Brendan Pendergast said.

“There is no reason these residents should sit back and just accept that this fire occurred, and accept the damage it did while incurring the substantial expense associated with re-establishing their properties.”

The action for 600 residents, thought to be the largest compensation claim of its kind in the state, began on May 16 in the NSW Supreme Court. It follows four similar class actions by Maddens over the 2009 Black Saturday bushfires in Victoria.

Endeavour Energy says the facts of the case will be determined through an independent and open review by the coroner.

“We don’t believe it’s in the interests of residents for us to add to the speculation about how and where these devastating fires might have started,” a spokesman said.

“The investigation is being carried out by various experts so the coroner can consider the evidence and make a finding about the cause of the fires. The company will fully support this investigation and continue to assist in every way.”

Maddens will allege the October 17 blaze at Springwood and Winmalee began after a “poorly maintained” tree – which had been identified as a hazard three months earlier – fell on power lines.

A hazard notice was issued to a Springwood property owner, asking him to trim the tree, but Maddens says state-owned Endeavour Energy was obliged to ensure it was complied with.

Mr Pendergast estimates the claim will exceed $200 million in property loss and damage.

Many of those who lost homes or suffered damage were underinsured or had no insurance.

In the four class actions Maddens has settled in Victoria the cause of the fires was poorly maintained power lines or surrounding infrastructure, plus weather events.

The Blue Mountains blaze destroyed 200 homes and damaged a further 200 properties.

The matter is listed to be heard at the NSW Supreme Court in August.