A woman has life-threatening injuries after a two-vehicle crash on Highway 401 in Ajax.
Provincial police said a tractor-trailer had blown a tire and was stopped on the left shoulder of the highway near Westney Road just after midnight on Wednesday.
Police said it appears an SUV drifted onto the shoulder and slammed into the rear of a truck.
The female driver of the SUV was ejected from the vehicle.
A male passenger was in the vehicle and suffered non-life-threatening injuries.
Police said neither drugs nor alcohol was involved in the crash.
The lanes were closed in the area but have since reopened.