Seven thousand resident were forced to flee through a single road as fires raged on both sides, according to Canadian news site the Globe and Mail.
The fast-moving wildfire also took out power, most cellphone service, the town hall and radio station.
The wildfire caught officials off guard. By midafternoon, officials had not made an evacuation order even as two wildfires burned on the outskirts of town.
“We kind of thought the thing was getting under control,” Mel Knight, an Alberta cabinet minister in charge of forest fire response, told the Globe and Mail. “What happened this afternoon is the winds picked up.”
Winds gusted as strong as 60 miles an hour Sunday.
By Monday, those winds had eased to 6-to-12 miles per hour but fires continued to burn.
The mayor said at least 30 percent of the town has burned down.
“It’s extremely devastating, our loss,” Slave Lake Mayor Karina Pillay-Kinnee told the Globe and Mail Sunday. “It’s difficult to articulate.”
On Facebook, Canadian radio station 102.3 shared information on how to find friends and family or donate to the Red Cross. On Twitter, Canadian broadcaster CTV shared photos of the fire and continuous updates from Slave Lake:
Here’s some videos captured on cellphone cameras of residents from Slave Lake: