CP Rail and members of the Transportation Safety Board  of Canada (TSB) continue their investigations into what prompted a freight train to unexpectedly stop on Thursday, a move that sent 15 cars off the track.

The derailment occurred late Thursday morning in the Lower Spiral Tunnel of Mount Ogden, east of Field, B.C. The train was travelling at a speed of approximately 22 kilometres per hour when its progress was halted.

Crew members surveyed the train and determined that 15 empty cars near the end of the train had left the track. The train was a mixed manifest train transporting varius commodities and products but officials confirm the derailed cars were empty.

TSB investigators from Edmonton and Calgary responded to the scene late Thursday night after hiking through deep snow with the assistance of Parks Canada.

The heavy snowfall is not believed to have contributed to the derailment but may play a factor in the cleanup process. Officials hope to have the tunnel cleared Saturday morning.

Members of the crew have been interviewed and an event recorded has been retrieved from the engine.

With files from CTV's Camilla Di Giuseppe