Two seniors suffered serious injuries after a single vehicle crash near Alliston Saturday morning.

The OPP say a vehicle went off the road for an unknown reason and struck a pole on Highway 89.

The driver, an 84-year-old man, is in serious but stable condition, police said.

The passenger, an 81 year-old woman, suffered life threatening injuries.

Simcoe County Paramedics transported the driver and passenger to local hospital. They were then airlifted to a Toronto area hospital.

Highway 89 was closed between Concession Road 5 and County Road 13 for several hours for the police investigation.

The investigation continues.