Four people were sent to hospital after a set of wheels flew off a transport truck on Highway 401.
The truck was on the eastbound side near McCowan. OPP say one of the wheels crossed the median. It was hit by a car, causing a chain reaction crash involving four other vehicles.
Two young women were taken to a trauma centre. They're expected to survive. Two other people had significant injuries.
It appears the driver of the truck didn't realize the wheel came off. Police eventually found them in Pickering.
The truck driver has been charged.