A 12-year-old boy and a 43-year-old man from the United States have been critically injured in a multi-vehicle crash on Highway 403 in Mississauga.
Ontario Provincial Police said two vehicles initially collided in the westbound lanes of the highway near Mavis Road just before 5 p.m.
The drivers, police said, shortly moved their vehicles to the right shoulder and got out to exchange information.
A short time later, a third vehicle collided with one of the vehicles, pushing it forward into one driver and a child passenger who were standing outside, police said.
Paramedics told CTV News Toronto that an adult male and a boy sustained serious, life-threatening injuries and were taken to trauma centres.
A third person was taken to a local hospital with non-life-threatening injuries, paramedics said.
In a subsequent update, police confirmed the man and the boy are U.S. residents.
The cause of the initial crash is unknown as well as the circumstances surrounding the subsequent collision.
Police closed the westbound lanes of the highway between Mavis Road and Erin Mills Parkway.
Police said the closure would remain until 10:30 p.m.
