Ontario Provincial Police say a man and a woman, both in their 60s, are dead after a head-on collision just west of Newmarket Thursday night.
Police said officers responded a collision between two vehicles on Highway 9, between the 11th and 12th concession at 6:15 p.m.
Const. Tracey Lacarte said a car with one male occupant and a pickup truck with two female occupants were involved in the collision.
Lacarte said the man was pronounced dead on scene. The two women were taken to hospital, one in Newmarket, the other in Toronto.
She said the woman in Newmarket has succumbed to her injuries, while the woman in Toronto remains in life-threatening condition.
It is not clear what led up to the incident.
The area has been closed for the investigation.
Witnesses or anyone with information is asked to contact the OPP Aurora detachment at 905-841-5777.