The BC Coroners Service has identified the woman killed Friday morning after a small boulder crashed through the windshield of her family car.

Calgary resident Janice Cairns was in the passenger seat of the vehicle when the approximately 30-centimetre rock flew off the tire of a passing truck.

It smashed through her windshield and struck the 36-year-old mother of two on the head. She died instantly.

Authorities say Cairns was vacationing with her family at the time of the accident. No one else in the vehicle was injured.

The Coroners Service and the RCMP are continuing to investigate.

With files from The Canadian Press