LAC-MEGANTIC, Quebec — Hazardous conditions hindered firefighters’ attempts Monday to search for some 40 people still missing after a runaway oil tanker train exploded over the weekend, killing at least five people, officials said.
Meanwhile, crews are working to contain 100,000 litres (27,000 gallons) of light crude that spilled from the tankers and has made its way into nearby waterways.
Quebec’s Environment Ministry Spokesman Eric Cardinal said special balloons are being used to block the oil from flowing through the sewer system and floating barriers have been set up to stop the oil from heading downstream.
The oil has reached the nearby town of Saint-Georges along the Chaudiere river and there are fears it could flow into the St. Lawrence River all the way to Quebec City.
Cardinal said officials remain hopeful they can contain more than 85 per cent of the spill.
Quebec provincial police Sgt. Benoit Richard said Monday morning there was no searching overnight because the situation remained too dangerous. He said only a small part of the devastated scene has been searched as firefighters made sure all flames were out.
The heart of the town of about 6,000 was leveled in the explosion — including a pharmacy, library, and a popular bar, Musi-Café, where several dozen revelers were believed to have gathered.
Sophie L’Heureux, a manager at the bar, had been working earlier in the night but went home for a rest. She was woken up by the explosion.
L’Heureux said she believed there were about three workers and about 50 people in the bar, including many close friends.
All but one of the train’s 73 tanker cars were carrying oil when they somehow came loose early Saturday morning, sped downhill nearly seven miles (11 kilometers) into the town of Lac-Megantic, near the Maine border, and derailed, with at least five of the cars exploding.
The growing number of trains transporting crude oil in Canada and the United States had raised concerns of a major disaster, and this derailment was sure to bolster arguments that a proposed oil pipeline running from Canada across the U.S. would be safer.
‘‘This is an unbelievable disaster,’’ said Canadian Prime Minister Stephen Harper, who toured the town Sunday and compared it to a war zone. ‘‘This is an enormous area, 30 buildings just completely destroyed, for all intents and purposes incinerated. There isn’t a family that is not affected by this.’’
The train’s oil was being transported from North Dakota’s Bakken oil region to a refinery in New Brunswick. Because of limited pipeline capacity in the Bakken region and in Canada, oil producers are increasingly using railroads to transport oil to refineries.
The Canadian Railway Association recently estimated that as many as 140,000 carloads of crude oil will be shipped on Canada’s tracks this year — up from 500 carloads in 2009. The Quebec disaster is the fourth freight train accident in Canada under investigation involving crude oil shipments since the beginning of the year.
Harper has called railroad transit ‘‘far more environmentally challenging’’ while trying to persuade the Obama administration to approve the controversial Keystone XL oil pipeline from Canada to the Gulf Coast. Greenpeace Canada said Sunday that federal safety regulations haven’t kept up with the enormous growth in the shipment of oil by rail.
Officials with the Montreal, Maine & Atlantic Railway said that despite the disaster, they feel transporting oil by rail is safe.
‘‘No matter what mode of transportation you are going to have incidents. That’s been proven. This is an unfortunate incident,’’ said Joe McGonigle, Montreal, Maine & Atlantic Railway’s vice president of marketing.
He said the company believes the train’s brakes were the cause. ‘‘The train was parked, it was tied up. The brakes were secured. Somehow it got loose,’’ he said.
McGonigle said there was no reason to suspect any criminal or terror-related activity.
Wayde Schafer, a North Dakota spokesman for the Sierra Club, has predicted such a catastrophe ever since crude began leaving the North Dakota by rail in 2008.
‘‘I think anybody could have foreseen this,’’ said Schafer, whose downtown Bismarck office is just two blocks from a rail line that carries several mile-long oil trains daily through the heart of the North Dakota’s capital city. ‘‘It seemed like a disaster waiting to happen and it happened.’’
Associated Press writer Rob Gillies and Charmaine Noronha contributed from Toronto. James MacPherson contributed from Bismarck, N.D.