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 worked to contain oil spilling in the Claudiere River which feeds into the St. Lawrence.
The Quebec government issued a statement saying the leak was "serious, but under control." The statement said the oil could spread as far as Quebec City.
Floating barriers have been set up to try to stop the oil from heading downstream.
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.
Many of those missing were believed to have been drinking at a popular downtown bar when the explosions occurred and rescuers were still not able to reach the area, Richard said.
"Hopefully we'll be able to open up more areas for searching during the day," he said.
Firefighters on Monday were focusing their efforts on two oil-filled cars dousing them with water and foam in an attempt to keep them from overheating and exploding.
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.
About a third of the community of 6,000 was forced from of their homes by the explosion and flames.
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.