Did someone tamper with the train?
The railway company responsible says someone shut down the lead locomotive of the train carrying crude oil after its staff had secured it. Once the lead locomotive was no longer running, its compressed-air brakes no longer worked.
Montreal, Maine and Atlantic Railway spelled out the theory in a press release Sunday. "The locomotive of the oil train parked at Nantes station was shut down subsequent to the departure of the engineer who had handled the train from Farnham, which may have resulted in the release of air brakes on the locomotive that was holding the train in place," the company statement said.
On Monday, company spokesman Yves Bourdon was asked on Radio-Canada if that meant someone tampered with the train or even if this was terrorism. "Everything is possible," he said.
Isn't there a backup system?
The convoy of five locomotives and 72 cars should also have hand brakes. Investigators from the Transportation Safety Board have recovered the black box and say they will be looking at the state of the train's air brakes and hand brakes.
"Certainly the manner in which the train was secured, both air brakes and hand brakes, we'll be looking very strongly at that," said TSB investigator Donald Ross.
Montreal, Maine and Atlantic Railway acknowledges that it does not have the full picture because the ongoing fire and the TSB investigation have prevented the company from completing its own probe. "We don't have complete information concerning this incident, but will co-operate with government authorities," the company said.
Why was a trainload of flammable liquids parked uphill from Lac-Mégantic?
Like other transportation workers, train engineers have to follow requirements for hours of work and rest. Montreal, Maine and Atlantic Railway has regularly parked its train at a yard in Nantes while their engineers get a cab to catch a 12-hour break at a hotel in Lac-Mégantic.
As scheduled, the convoy of five locomotives and 72 cars was idling outside Nantes while waiting for a new crew. Around 12:15 a.m. Saturday, the Nantes fire department was called after a passerby noticed that one of the train's diesel engines had caught fire. A leak near a locomotive wheel had left diesel trickling down for several kilometres before Nantes, according to Le Journal de Québec.
The company says its staff made sure the train was secure after the Nantes fire. At approximately 1:15 a.m., the train then began rolling toward Lac-Mégantic.
How long will it take to establish the number of victims and identify the remains?
For the aggrieved community, the wait will be long. there will also be a long wait.
The police won't even reveal the exact location where bodies were found because it could lead to speculation about their identities – and next of kin have yet to be notified. Dental records and DNA tests will be required because the remains are so badly burned.
In a grim interview with Radio-Canada, chief coroner Louise Nolet cautioned that her staff's work will be challenging because remains might come in fragmentary body parts and will need to be matched together. She said the task is further complicated by the presence of the remains of dead household pets.
On Monday the official death toll rose to 13 as officials searched new areas where the flames are under control, said provincial police spokesman Sergeant Benoît Richard, with some 50 people missing.
There were no search operations overnight because the blast scene is still considered too risky so the official death toll remains at five dead and 40 missing, provincial police spokesman Sergeant Benoît Richard said Monday morning.
So far, the first five bodies recovered have been transferred to the coroner's lab at the provincial police's Parthenais headquarters in Montreal, while the three others will be transported there later, said Geneviève Guilbault, a spokeswoman for Quebec's coroner's office.