Durham police say a 31-year-old woman has been airlifted to hospital after being struck by a car while waiting at a bus stop in Ajax.
Officers were called to the scene at Taunton Road East between Harwood Avenue and Salem Road around 11 a.m.
An investigation revealed the woman was struck after two vehicles came in contact with each other. One of the cars rolled into a ditch and landed upside down. The driver had to be extricated and suffered minor injuries.
The driver of the other vehicle was not injured.
The pedestrian was taken to a Toronto trauma centre with serious injuries.
Taunton was closed for several hours as police investigated the collision.