While the town of Lac-Megantic assesses the damage from an immense series of explosions that came after a train transporting crude oil came off the tracks, questions are being raised about the overall safety of transporting oil products to market.

Investigators still don’t know why the train, which was stopped overnight in a nearby rail yard, came loose and rolled into the Quebec community, 250 kilometres east of Montreal.

The train, owned by Montreal Maine & Atlantic., had stopped for a crew change shortly before midnight Friday. Somehow, while the 73-car train was unattended, it got loose.

The cars, heavy with their crude oil shipment, quickly barrelled down the tracks and went off the rails when they reached Lac-Megantic. The oil caught fire and wiped out some 30 buildings in the town.

Edward A. Burkhardt, chairman of the Chicago-based MMA, said the engineer had secured the brakes before heading to his hotel. “We’re taking the locomotive engineer’s statement as a fact that he applied the brakes," Burkhardt said.

Even before the cause is known, the immediate impact of Lac-Megantic disaster –- a town in ruins and an environmental disaster in the works with oil spilling into a nearby lake -- has renewed the debate over how oil is transported across the country.

"We're seeing more and more petroleum products being transported by rail,” NDP Leader Thomas Mulcair said Saturday. “There are attendant dangers involved in that, and at the same time the Conservative government is cutting transport safety in Canada -- cutting back the budgets in that area."

“We’ve got to get beyond this system of self-regulation,” Mulcair added. “This is another example of where the government has been cutting in the wrong area.”

Both CP Rail and Canadian National Railway are increasing shipments of crude oil as production ramps up from the Alberta oilsands.

Those two companies alone moved more than 30,000 carloads of crude to various North American markets last year, and business is expected to double in 2013.

This dramatic jump in the oil business has come at the same time as train companies have taken on more responsibility for safety.

Transport Canada routinely monitors rail lines, but there's been a gradual shift for the rail companies to police themselves and check their rail lines.

Every time there’s an incident or accident, questions are raised about who was checking the lines and trains.

Recent incidents include:

  • Just last week, there was a near-disaster on the Bonnybrook Bridge in Calgary. The flood-damaged structure had buckled under the weight of four rail cars carrying highly flammable liquids used to dilute raw oil.
  • In May, a freight train jumped the tracks in rural Saskatchewan and spilled more than 91,000 litres of oil.
  • In April, about 20 freight cars, including two that were carrying light sweet crude oil, went off the tracks near White River, Ont.
  • In March, another Canadian train derailed in Minnesota. The Minnesota Pollution Control Agency said 76,000 litres of oil leaked onto frozen ground.

Emile Therien, the former president of the Canada Safety Council, says Saturday’s incident will be the subject of a major investigation by the Transportation Safety Board, and it should also be the focus of some rethinking about the government’s role in inspections.

“There’s no question they provide a valuable service,” Therien says of the train industry, but railroad companies have been “doing their own thing” with safety.

“Transport Canada has got to get back in the game,” he said, “There's no question about it.”

In Calgary Saturday afternoon, Prime Minister Stephen Harper promised a full investigation into the incident. He plans to tour Lac-Megantic on Sunday.

With a report by CTV's Richard Madan