Fire crews have the worst of the flames in Fort McMurray under control, and are working to secure the city's infrastructure before allowing evacuees to return home, according to the chief of the fire department.

Chief Darby Allen announced that his crews have "beat" the fire in an optimistic video shared by the regional municipality of Wood Buffalo's Twitter account late Tuesday night.

"We think we've got this thing beat in (Fort) McMurray so we're looking pretty good," the fire chief said in remarks directed at the city’s approximately 80,000 evacuees.

"I just want to let you know we just can't let you back until it's safe," he said. "We've got to check electricity, water – all that stuff."

Allen promised evacuees they will be allowed back into the city as soon as possible, and urged them to remain patient in the meantime.

"We'll get it," Allen said of the fire.

He added that emergency crews are still "worried" about communities south of the city.

The province of Alberta has reopened a stretch of Highway 63, the main route that runs north-south through Fort McMurray. However, there is no set date to allow residents to return to their homes.

An estimated 2,400 buildings have been burned by the fire since it breached city limits last week.

Officials are now working on plans to return evacuees to their homes, and to rebuild the fire-ravaged city. The Canadian Red Cross says it has raised more than $60 million for relief efforts. The governments of Canada and Alberta have pledged to match all individual donations to the charity.

Prime Minister Justin Trudeau says he will visit the city on Friday.