WA Police Arson Squad pinpoint ignition point of Geraldton bushfire that destroyed home

Arson squad officers believe they have pinpointed the ignition point of a blaze that tore through 160 hectares of land, left two homes uninhabitable and completely destroyed another in WA's Mid West.

The fire in Geraldton, about 420 kilometres north of Perth, was first reported on Sunday morning.

Hundreds of firefighters, four water bombers and two helitaks (fire suppression helicopters) were called in to battle the fire that spread through the northern suburbs of Geraldton from Spalding to Waggrakine, Moresby, Bluff Point, Sunset Beach, and Glenfield through to Monday night.

As tired residents returned home to survey the damage, some of whom had been unable to do so for 48 hours, the focus turned to the cause.

The origin point has been identified in bushland bordering a residential street in Spalding.

On Monday the Department of Fire and Emergency Services said early indications pointed to the fire being deliberately lit.

DFES incident controller Brent Allen said the fire was being treated as suspicious and that Strike Force Vulcan was on the ground.

"At the moment we've got DFES and police arson squad investigators here and they're trying to determine the cause of this fire," he said.

"At the moment it's undetermined, although investigations are ongoing."

Mr Allen said police would be using every resource available to determine the cause.

"This early in the season, we need this to be stamped out," he said.

"There is no evidence to suggest right now that it has been deliberately lit — police are still working on that, but they'll get to the bottom of it and throw everything they can at it to ensure that things like this are prosecuted."

Police are offering a $25,000 reward for any information that leads to a conviction.

Community rallies around responders

Mr Allen said crews were fatigued but buoyed by the support of the community.

"The outpouring of support from the community to first responders and to the affected community has been incredible," he said.

"I've never seen such a level of community outreach and it is just fantastic."

The sentiment was echoed by City of Greater Geraldton Mayor Jerry Clune.

"Everyone is so grateful for the people that have come to fight the fires — they've come from near and far," he said.

Mr Clune said people were looking for answers to the cause of the blaze.

"The idea that the fire was sparked deliberately has led to anger and frustration from some within the Geraldton community," he said.

Mr Clune has urged people to remain calm and let police deal with the investigation.

He said the fire had brought out the best of the community.

"Being an old firefighter myself, you do see the best of people when you do have a fire," he said.

"People just down tools and come and help throw everything at it you can."

A community fundraiser has been organised in town for Friday, with all donations to go towards the support of those affected, including the couple who lost their home.