Investigators call Strathroy CN train derailment probe 'complex'

Investigators working to determine what caused a CN freight train to derail inStrathroy, Ont.earlier this monthadmit there is no obvious cause, but they continue to zero in on the first two cars that left the rails.

No one was hurt when 13 cars in the 120-car CN freight train jumped the tracks early in the morning ofJuly 19. The incident damaged the Metcalfe Street rail crossing and suspended Via rail passenger service through the area for two days.

A railcar loaded with cement appears to have left the track first in theincident, followed by an empty tanker that had been hauling liquefied petroleum gas, Transportation Safety Board investigators said.

"You always try to identify the first car off and that's what drives you as you go forward with theinvestigation," said Rob Johnston,managerof the central region's rail/pipeline investigations unit.

Other factors being looked at are theoperation of the train, the condition of the track and the condition of the rolling stock.

Some of those details, Johnstonsaid, will emerge after an in-depth look at the train's black box and more interviews with the conductor.

"In this particular case, there is no smoking gun where there's a definitive 'yes'. This one is going to be a little more complex and is going to take up a little more time," he adds, noting investigators will take as long as necessary to find answers.

Still, he estimates it will be at least a year before a final report is even close to being completed.