A Burnaby, B.C., woman and her two young daughters were killed in a crash on the Trans-Canada Highway near Rogers Pass in eastern B.C. Wednesday.

Police say for some unknown reason, the woman's Suzuki SUV crossed the centre line on a straight stretch of road and was struck by a tractor trailer unit.

The 36-year-old woman and her daughters, aged four and six, were killed instantly.

The driver of the truck was not injured.

Police say the three victims were travelling from Calgary to their home in Burnaby, and their names will not be released at the request of their family.

The RCMP and the B.C. Coroner's Service are investigating the cause of the crash.