A cracked wheel set may have played a role in a fiery derailment near Plaster Rock, New Brunswick, a spokesman from the Transportation Safety Board said.
Guy LaPorte told a news conference Thursday that TSB investigators discovered a crack in a wheel on a rail car that was located near the front of the train. The crack caused the wheel to loosen from its axel, allowing it to shift toward the centre and fall to the ground, he said.
A total of 19 cars came off the tracks on Tuesday night, including a number that were carrying crude oil and liquefied petroleum gas. About 150 people near Plaster Rock were forced out of their homes as a result of a fire at the site of the derailment, which was still burning on Thursday morning.
Mr. LaPorte said investigators are also aware of a broken rail at the site of the accident. He said it is still too early for the TSB to comment on the specific causes of the accident, noting that the investigation into what happened could take months.
The crude oil on the train was being carried in DOT-111 tank cars, Mr. LaPorte said. Questions have been raised in recent months about the safety of the older model DOT-111 cars, which are believed to be more susceptible to corrosion and rupture.
The train that derailed and exploded in Lac-Mégantic, Que., was carrying crude oil on DOT-111 cars. The accident killed 47 people last July.
Early reports suggest the train had been inspected during a stop in Montreal and was allowed to proceed toward New Brunswick, Mr. LaPorte said.
The TSB will conduct witness interviews and examine photos of the wreckage to try to determine what happened and whether to recommend additional safety measures. The agency does not lay blame for accidents.