A woman was killed after her vehicle veered off a highway and plummeted down a steep embankment into a river near Sayward, police say.

The single-vehicle crash occurred on the Island Highway about 1.5 kilometres southeast of the Sayward Road Junction just before 9 p.m. Thursday.

Police say the vehicle crossed the centre line and launched over the side of the road, travelling some 45 metres before landing in the Salmon River.

Bystanders quickly made their way down to the vehicle and pulled the lone occupant, a 50-year-old North Island woman, to shore.

They attempted to perform CPR on her but were not successful, according to police.

Sayward RCMP Cpl. Kim Graham said the cause of the crash is still under investigation.

“A witness had been following the vehicle and it just gradually veered off, left, and got launched over the embankment,” said Graham. “We’re just determine if there was a medical issue with the driver or not.”

She said police were in the process of notifying the victim’s next-of-kin.

Campbell River Search and Rescue also attended the scene to search for any other possible occupants.