The regional government said two other neighborhoods, Abasand and Waterways, had sustained "serious loss." Alberta Premier Rachel Notley said a total of about 1,600 structures have been destroyed in Fort McMurray."There are certainly areas within the city that have not been burned, but this fire will look for them and it will find them and it will want to take them," said Chief Darby Allen of the Fort McMurray fire department.
The province declared a state of emergency for what was shaping up to be Canada's costliest natural disaster.
Prime Minister Justin Trudeau said the military can deploy air force planes to the stricken city as needed. Fort McMurray International Airport suspended all commercial flights.
'Extreme wildfire behavior'
It was the second major blaze in the oil sands region in a year. Last May, wildfires led to the evacuation of hundreds of workers from the region, and a 9 percent cut in Alberta's oil sands output.
The wildfire's knock-on effects on oil sands operations escalated on Wednesday, with five companies including Suncor Energy and Husky Energy reporting reduced production either because workers had been affected by the evacuations or because of precautionary pipeline shutdowns. The impact on crude production volumes was not immediately clear, but Suncor said late on Wednesday it had shut its base plant operations - its largest oil sands mining site with a production capacity of 350,000 barrels of oil a day.
Its other thermal oil sands sites were operating at reduced levels.
Officials said very hot and dry conditions meant "extreme wildfire behavior" on all fronts around the fire.