The known death toll from Saturday's Quebec train explosion jumped to 13 on Monday afternoon. According to Reuters, local police have confirmed that at least 13 people were killed in the crash that destroyed the small downtown of Lac-Mégantic. Thirty-seven more are still missing in the wreckage of the crash, which could become Canada’s worst accident in years.

The driverless oil tanker derailed in Lac-Mégantic around 1 a.m. Saturday morning and exploded, destroying dozens of buildings in the center of the town near the Maine border. Fires blazed at the scene of the crash for well over 24 hours, hampering efforts to rescue possible survivors.

Initially, responders reported that one, then three and then five people had died in the crash while 40 were missing. Because of the high levels of destruction in Lac-Mégantic’s downtown center, police are not optimistic that many of the missing people will be found alive.

Following the crash and its resulting explosion, more than 2,000 people were evacuated from Lac-Mégantic, a town of about 6,000 residents located about 155 miles east of Montreal and 10 miles west of Canada’s border with Maine.

If 50 people are confirmed dead in the Lac-Mégantic explosion, it would make the crash the deadliest accident in Canada since a Swissair jet crashed into the sea off Nova Scotia in 1998, killing 229 people.

The railway’s operators believe that a runaway train was the cause of the accident. Edward Burkhardt, CEO of Rail World Inc., which owns Montreal, Maine & Atlantic Railways, blamed faulty brake systems. Initially, the train was parked uphill before it derailed, and while Burkhardt believes the brakes were properly applied, he said their pressure gradually leaked off, leading to the derailment.

"If brakes aren't properly applied on a train, it's going to run away," said Burkhardt. "But we think the brakes were properly applied on this train. We've had a very good safety record for these 10 years. Well, I think we've blown it here."