Three people are dead and one person has been airlifted to hospital with serious injuries after a head-on collision in Pickering, Ontario Provincial Police confirm.

According to OPP Staff Sgt. Dean Korn, a Mercedes car was headed eastbound on Hwy. 7 at around 12:10 p.m. when it collided with a westbound BMW that was attempting to pass another vehicle near Sideroad 28.

Korn said that investigators are still looking into the cause of the crash but believe that weather could have been a contributing factor.

“It is very windy out here, very cold; the snow is drifting across the highway at certain locations so it is possible that contributed to the collision. We are still investigating that and hope to have some more answers a little bit later on,” he said.

Ornge say the victim who was airlifted to hospital is a woman in her 20s who had sustained serious upper body injuries. The other victim taken to hospital has minor injuries, police say.

Police say that a Durham Region transit bus has been brought to the scene in order to provide shelter to emergency responders amid the extreme cold.

“Weather obviously is playing into this,” Korn said. “It is very cold.”

Korn said that there were four occupants in the BMW and one in the Mercedes.

Hwy. 7 was closed between Sideline 26 and Sideline 28 until 5:20 p.m. to allow for a police investigation.