Quebec provincial police said the official death toll, which stands at five, and missing persons list didn't change overnight.
The area surrounding the derailed tanker cars has remained largely off limits to anyone other than fire crews as they tried to bring the flames under control and prevent further explosions.
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"There’s a been a lot of work that has been done on the scene during the night, and hopefully we’ll get some more areas that we can search during the day — but of course, that is the firefighters responsibility," Quebec provincial police Sgt. Benoît Richard said Monday morning.
Police were meeting with family members of those still unaccounted for today to build files on the missing.
Two of the five confirmed dead have been sent to Montreal for identification, said Geneviève Guilbault, a spokeswoman for the Quebec coroner's office. The three others will be transported later today.
Public health and environment officials say they're still assessing the impact of the massive oil leak and fire on the area inside and outside of the security perimeter.
Mélissa Généreux, public health director for Quebec's Eastern Townships, said air quality testing in the area outside the town's core was positive.
"There is no further health risk," she said. "In the downtown, there are still some small anomalies, but frankly, we're going in the right direction, and we're confident today that levels will be completely restored."
Testing is still being done on dust, smoke and oil particles that have built up on homes and yards near the blast site.
"The situation varies from house to house and sector to sector," Généreux said, adding they're still assessing the best way to conduct the cleanup of that material.
Thin layer of oil
Quebec Environment Minister Yves-François Blanchet told CBC’s Quebec AM that he flew over the Chaudiere River Sunday to see the extent of the damaged caused by the oil spilled from the derailed tankers.
“What we have is a small, very fine, very thin layer of oil which, however, covers almost entirely the river for something like 100 kilometers from Lac-Megantic to St-Georges-de-Beauce,” he said.
“This is contained at St-Georges-de-Beauce for the time being, most of it, or almost entirely, and we are very confident we will be in a position to be able to pump most of it out of the river. However, there will be some impact.”
He said an estimated 100,000 litres of oil spilled into the river.
Officials at the scene said contamination to the soil appears to only affect the surface, but further testing will be done by the environment ministry. They stressed that rehabilitation work is the immediate priority.
Medical services located inside the safety zone will be relocated until they are able to return to their spaces, officials said.
Residents still displaced
The town's mayor, Colette Roy-Laroche, implored residents to follow the directions of authorities and stay outside of that zone unless given authorization.
"We’re aware that people are worried about their homes and their anxious to return to their homes, but we need to do that safely," she said. " That’s what we are looking at now."
As many as 2,000 were forced out in the hours following the explosions. Many relocated to the homes of friends and family, while about 150 people took refuge at a temporary shelter set up by the Red Cross in a local school.
After viewing the devastation in the town yesterday, Prime Minister Stephen Harper likened the downtown of Lac-Mégantic to a "war zone."
The incident has shone the spotlight on the contentious political debate over oil transportation, and Canada's rapidly expanding oil-by-rail industry which has seen a stunning 28,000-per-cent increase over the past five years.
The search for victims in the charred debris has been hampered by the fact two of the train's cars continued to burn Sunday morning, creating concerns of other potentially fatal explosions.
CBC reporter Stephen Puddicombe said from the scene Monday morning that today will be the first chance for the Transportation Safety Board of Canada to access the crash scene.
"It's going to be just a grim day for many, many people down at this site," he said.
Provincial police were initially hesitant to estimate the number of people unaccounted for and offered a figure Sunday for the first time since the derailment.
"We have to be careful with that number because it could go up or down," Quebec provincial police Lt. Michel Brunet told a news conference.
Three pathologists have been called in to take on the grim task of identifying human remains.
Hears screams of friends
About 30 buildings were destroyed, including Le Musi-Cafe bar where partygoers were enjoying themselves in the wee hours of a glorious summer night.
Puddicombe said he talked to a man who was in the bar when the derailment happened, but was able to get away.
"He said he hasn't been able to sleep. All he can hear are the screams of his friends."
The multiple blasts over a span of several hours sent people fleeing as the explosions rocked the municipality of 6,000, about 250 kilometres east of Montreal.
- Before and after: Aerial views of the destruction in Lac-Mégantic
- Zoom: Lac-Mégantic blast site
"It's a beautiful downtown here that's been destroyed …There's really going to be a need for substantial reconstruction," Harper said after seeing some of the damage.
"I saw this on the international news yesterday … Everywhere people are talking about this."
Harper scolds Mulcair
In terms of financial aid, Harper said there is a formula that calculates the federal response for events like this.
When asked about railway safety concerns, Harper said it was too early to discuss causes. His office issued a statement later in the day through social media, scolding Opposition Leader Tom Mulcair for suggesting lax federal regulations might be to blame.
"We don't have a lot of the facts, and it would really not be responsible to comment without all the facts," Harper said.
The prime minister said the federal Transportation Safety Board, and also the police, would be investigating. Police are treating the area as a possible crime scene.
Harper promised to draw lessons from the TSB conclusions to prevent a repeat of such a tragedy.
"We will conduct a very complete investigation," Harper said, "and we will act on the recommendations."
Harper greeted and shook hands with people at a shelter for evacuees, which was set up at a high school after nearly a third of the town's residents were forced from their homes Saturday.
Throughout the day Sunday, people streamed in and out of the shelter.
Health-care workers offered services such as psychological counselling, while volunteers handed out snacks and bottled water.
Local people recall blasts
Locals shared their experiences from the night of the blasts.
A few people recalled how they darted into the streets after the explosion and ran alongside neighbours, some wearing nothing but boxer shorts.
Others who gathered outside the shelter Sunday hugged and wiped tears as they braced for bad news about unaccounted-for loved ones.
Henri-Paul Audette headed there with hope of finding his missing brother.
He said he had been told by an acquaintance that his brother, Fernand, had registered at the shelter. But, when he got there, he saw that his 58-year-old sibling's name wasn't on the list.
Audette, 69, said his brother's apartment was next to the railroad tracks, very close to the spot where the train derailed.
"I haven't heard from him since the accident," he said.
Locked the brakes
"I had thought … that I would see him."
Another man who came to the shelter said it's difficult to explain the impact this incident has had on life in Lac-Mégantic.
About a third of the community was forced out of their homes.
On Sunday the railway, Montreal, Maine & Atlantic, said the locomotive was somehow shut down after the engineer left the train.
It said he had locked the brakes before leaving the train.
That shutdown "may have resulted in the release of air brakes on the locomotive that was holding the train in place," the statement said.
"As mentioned above, we don't have complete information concerning this incident, but will co-operate with government authorities as they continue their investigation."
Earlier warning signs
The president of the railway's parent company, Rail World Inc., had said the train was parked uphill of Lac-Mégantic before it became loose and began careening into town.
There might have been warning signs hours before the disaster.
Witnesses in the neighbouring community of Nantes, where the train had been parked before breaking loose, said Sunday that they had seen sparks and a cloud of diesel smoke as it came to a stop a few hours before the derailment.
Lac-Mégantic's fire chief said that Nantes firefighters had answered a call about a fire aboard the locomotive less than three hours before the train rumbled into Lac-Mégantic.
Federal TSB officials said they planned to interview all possible participants as part of what they called a "360-degree," top-to-bottom, investigation.
They said they had retrieved a so-called "black box" from the train Sunday.