No casualties have been reported from the monster blaze, which lashed at residences and motor home parks, causing traffic chaos as people scrambled to safety.
But authorities warned that the next 24 hours would be critical.
"This fire is absolutely devastating," said Prime Minister Justin Trudeau. "It's a loss on a scale that is hard for many of us to imagine."
Alberta emergency services announced shortly before midnight Tuesday that all of Fort McMurray, a city of about 100,000, was under a mandatory evacuation order. They said earlier that the northern edge of the inferno was "growing rapidly."
Mayor Melissa Blake said predictions of what would happen not only came true but were even worse than imagined.
"This is a very explosive situation," warned Bernie Schmitte of Alberta's agriculture and forestry ministry. "These are catastrophic wildfires."
The fire has destroyed some 2,000 residences in the city's most outlying districts and ravaged 10,000 hectares (25,000 acres), he said.
More than 80,000 have fled the city, located 400 kilometers north (250 miles) of the provincial capital Edmonton, according to Scott Long of Alberta's emergency management agency, with the area around the airport the only one not under an evacuation order.
"We are going to ask you to stay where you are so that we can utilize all roads," he said.
Nine air tankers, a dozen helicopters and some 250 firefighters were battling the flames, and the military was put on alert.
"Obviously, Fort McMurray being evacuated has been extremely difficult, not just for the province and officials, but for the folks who live there," Trudeau said.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
