GATINEAU, Que. — The Transportation Safety Board says a freight train derailment in northern Ontario was caused by the complete failure of a previously cracked rail.
The incident took place on Jan. 13 as the Canadian Pacific train was travelling about 34 kilometres east of Nipigon.
The TSB says the 31-car train included seven dangerous goods tank cars loaded with propane.
The board's investigation found that a cracked rail gave way completely as the train drove over it, causing 21 cars including the propane tanks to derail.
They say the crack in the rail went undetected despite regular inspections because it was located behind joint bars, making it difficult to spot at a time when the track base was covered in snow.
The TSB says CP's safety procedures were lacking in the incident. One crew member sustained minor injuries after inhaling propane that leaked from the train.
"Despite the conductor's repeated exposure to the propane, medical assistance was not specifically requested until two hours later," the board wrote in its report.
"The investigation found that CP training, procedures, and guidelines were insufficient to protect the conductor from the hazards associated with the derailment and release of a large volume of propane while conducting the site assessment. "
The TSB is an independent agency that investigates marine, pipeline, railway and aviation transportation occurrences. Board investigations do not assign fault or determine civil or criminal liability.