The threat has eased in the Mt Stapylton and Bellfield areas in the Grampians National Park after residents were told seek shelter on Tuesday afternoon.

Conditions were also better on Wednesday morning around a bushfire at Newtown near Ballarat after residents were told to evacuate after a grassfire spread into a forest and morphed into a bushfire.

The third fire around Pomonal, also in the Grampians, is still to be brought under control and there are unconfirmed reports multiple homes have been lost in the town.

Five country firefighters suffered minor injuries after their truck was involved in a burnover at a fireground at Pomonal on Tuesday night.

The firefighters were pre-positioned in the town and tasked with protecting homes and critical infrastructure, Forest Fire Management Victoria chief Chris Hardman said.

“When the wind change came through, the fire moved very rapidly into Pomonal and those firefighters were caught between the fire front and the work they were doing in protecting communities,” Hardman said.

Authorities are still working out how many homes have been destroyed in the fires in Pomonal.

“We don’t have a full understanding of the fire front and the impact it’s had on the township, but it certainly has impacted sections of the Pomonal township and we’ve had some losses,” Hardman said.

Impact assessment teams will touch down on firegrounds on Wednesday to assess any loss of life and damage to properties.

Some of the worst affected areas included eastern and south eastern suburbs of the city, like Waverley, Burwood East, Vermont South and Bentleigh.

At its peak, an estimated 500,000 properties lost power as towers collapsed in heat, transmission lines tripped and multiple generators disconnected from the grid.

“These power outages are due to storm activity, strong winds and lightning causing damage to the electricity network,” the Australian Energy Market Operator said in a statement late on Tuesday.

Wind gusts of more than 120km/h struck six major transmission towers near Geelong while extreme heat knocked the state’s largest electricity plant off-line.

Authorities warned it could take days to address high voltage transmission issues still affecting more than 200,000 homes.

Traffic lights have also been impacted and there’s a likelihood some schools may have to close on Wednesday.

As of 6am Wednesday, the Victorian State Emergency Service had received more than 2750 calls for help since midday on Tuesday.

Some 1750 calls have now been cleared and authorities are working through the other 1000.

Home Affairs Minister Clare O’Neill, a Victorian, said it was surprising so many homes lost power.

“There’s some really important questions to ask and answer here about how it’s possible that a country like Australia can lose power for 500,000 people because of a storm,” she said.

“But I do think those questions are for later.

“Our hearts and our actions and thoughts have to be with those families that are really suffering.”

Tuesday was a scorcher for multiple states, but Victoria suffered the worst with temperatures surpassing 40C in some parts of the state.

“It’s been hot, sizzling,” the Bureau of Meterology’s Kevin Parkyn said.

“We’ve seen 41.7C at Walpeup, 41.4C at Hopetoun there up in the northwest of the state.

“Incredibly 41C at Avalon there ahead of the wind change and the temperature dropped by about 15 degrees down to 26C in 15 minutes.”

A catastrophic fire danger rating was declared for some parts of the state on Tuesday, the first since the deadly Black Summer of 2019-20.

– AAP