It was early morning and pitch dark in the tiny town of Nantes, Que., when a train loaded with crude oil began moving down the tracks toward neighbouring Lac-Mégantic. A steady grade helped the cars pick up speed, eventually sending them hurtling toward the heart of the town below.
The train went off the tracks and exploded into flames around 1 a.m., instantly wiping out 30 buildings and inflicting a death toll that is expected to climb.
The damage wrought by the derailment could be seen kilometres away. But what set off the devastation is a mystery. Now, as investigators seek to make sense of the incident, questions are being raised about what roles a fire just a few hours earlier and failure of air brakes might have played.
At about 11:30 p.m., a fire had broken out in one of the train's locomotives shortly after the company that owns the train says its engineer had secured it on the tracks and headed to a local hotel for the night. Firefighters quelled the blaze and left the train in the hands of two representatives from Montreal, Maine & Atlantic Rail, according to Nantes fire chief Patrick Lambert.
The locomotive was "shut down subsequent to the departure of the engineer," according to the company, depriving its air brakes of the power needed to keep the load from careening downhill.
The crash is also drawing attention to a growing debate about the movement of energy resources around North America, with some railway owners hoping to make their services an alternative to pipelines. And it is raising questions about the safety of single-operator rail cars and the limited options for municipalities to refuse when companies want to move hazardous materials inside their limits.
Some residents of Nantes and Lac-Mégantic said they have expressed concerns about the train's safety in the past, and many felt the company had not been responsive.
The company issued a statement on Sunday that its staff are preparing to deal with residents' immediate needs and establish a process for handling damage claims.
Danielle Veilleux lives directly across the street from the train tracks in Nantes and several hundred metres from the stretch of track that runs parallel to the main line and allows trains to be parked while others pass.
She said she looked out her window at about 10:45 p.m. on Friday and saw sparks coming from the chimney of the train's locomotive, along with a large, noxious cloud.
"It smelled bad, like diesel," Ms. Veilleux said. But she said she did not think too much about it because she had seen sparks coming from the train's chimney in the past.
Joe McGonigle, Montreal, Maine & Atlantic Railway's vice-president, said a representative "was there to assist the fire department" on Friday night.
"But the crew member wasn't the last man to see that train. We know that," he added.
Alex-Catherine Gagnon of Lac-Mégantic said she was getting gas on her way home from work when she saw the train hurtle by. "My head was spinning it was going so fast," she said. "I told my friend, 'That's really dangerous – imagine the damage it could cause.'"
Minutes later, she saw a "huge ray of light" in the sky as the train burst into flames in the town's centre.
Yves Faucher said he was in his living room when the curtains suddenly lit up "as if it was daytime."
"I went outside to see what was going on. There was a huge mushroom-shaped cloud of flames," he said.
He got on his bike and started knocking on his neighbours' doors to warn them to leave and helped evacuate the local seniors' centre.
At one point, Mr. Faucher said he threw his bike between cars of the crashed train and crawled after it to try to help those on the other side.
Firefighters from several other stations responded to the blast, but the town's own station was engulfed in the explosion, according to a resident who was on the street nearby.
Firefighters from Nantes said they were called to a fire on the train tracks around 11:30 p.m. – less than two hours before the fatal crash.
Mr. Lambert said fire crews were on the scene within seven minutes of the call. He said the fire, which was in the train's locomotive, was out and the train was believed to be secure by midnight, and the train was left in the care of two employees from the rail company.
On Sunday, nine black, cylindrical tanks and one locomotive sat on the train tracks at the siding.
Mr. Lambert said the containers had been hauled up from Lac-Mégantic using a different locomotive. Large, black oil spots dotted the tracks north of the parked locomotive. In one spot, several black, greasy towels sat in the middle of the track.
Beneath the locomotive and two of the tanks, the dirt and rocks between the railway ties looked as though they had been dug up and scooped to either side of the tracks. Deep holes, three across, ran between the tracks and one on either side.
André Lavigne said the holes between the tracks are the result of repair work the rail company completed about two weeks ago. He said the train used to tilt to one side, and the company had come in to adjust the tracks so the cars would stand more upright.
With reports from Sophie Cousineau, Sean Silcoff and Guy Dixon. Verity Stevenson is a freelance writer.