The derailment occurred at about 6:30 a.m. on Thursday and was reported to CN by the train crew.
No injuries or fires were reported on Thursday morning.
Early reports are that most of the cars that may be involved are residue cars, last carrying flammable liquids, CN said.
More information is expected when CN crews arrive on the scene.
The railway said "crews, including senior officers in our operating, engineering, dangerous goods and environment departments are responding" to the derailment.
More to come.
Clarification : An earlier version of this story stated one of the cars that went off the tracks may have been carrying flammable liquids. It has been changed to "early reports are that most of the cars that may be involved are residue cars, last carrying flammable liquids.(Mar 05, 2015 11:45 AM)