Firefighters were digging in for a long battle to extinguish a Golden Gully factory fire as the sun set on November 19.
It "will probably burn into the night," acting assistant chief fire officer for the district, Darren Eenjes, told the Bendigo Advertiser.
He was helping oversee 200 firefighters and emergency crew members in what had become a complex operation.
Firefighters were originally called to a fast-moving grass and scrub fire in Golden Gully at about 2.20pm.
They saved homes and other properties on Belle Vue Road but the wind was too strong to stop flames sparking in a large number of wooden pallets at the back of United Tools' factory on Hattam Street, Mr Eenjes said.
"It entered the factory. I'm sorry to say the factory has been totally engulfed in fire," he said.
"Internally there's been a 40 per cent collapse of the premises."
Firefighters have contained the bushfire and have more crews into the city from across Victoria to focus on the factory.
"The complexity now is the factory fire, which is issuing a lot of potentially toxic black smoke to the eastern suburbs of Bendigo including Flora Hill and that Quarry Hill area," Mr Eeenjes said.
He had not been told of any injuries or other concerns at the fire.
Homes and other properties along Belle Vue Road were evacuated soon after the fire erupted with the help of police and other emergency crews, Mr Eenjes said.
Several fences could have been damaged but it was not thought any homes or other properties had sustained serious damage, according to the latest information.
It is not yet clear what caused the fire but the CFA and police expected to launch a full investigation.
Mr Eenjes and other CFA leaders are now working out shifts for firefighters and putting the finishing touches on catering operations to make sure everyone is fed.
Teams from Kyneton and Melbourne are being brought up to Bendigo's fire station to cover any other fires that break out overnight, Mr Eenjes said.
The help would be welcomed by CFA crews that had endured an "extremely busy and arduous weekend", Mr Eenjes said.
They had spent the weekend racing to out-of-control burn-offs, he said.
"It created quite a number of issues for our firefighters. With fire restrictions for the City of Greater Bendigo coming in ... that will reduce that demand but we need to consider that the Macedon Ranges Shire will not be in for another week yet," Mr Eenjes said.
"We had a reasonable-sized fire there at Riddells Creek this afternoon."
Fire restrictions for the Bendigo area were coming into effect at 1am on Monday, November 20.
Note: A previous version of this story incorrectly stated the factory was a Total Tools business. It was United Tools.
Sign up for our newsletter to stay up to date.