The investigation continues into a crash on the 401 near Dutton.
Emergency crews responded to the eastbound lanes of the highway between Union Road and Colonel Talbot Road on Thursday at 2 p.m., following a collision involving two commercial vehicles and two passenger vehicles.
Five people were taken to hospital with minor injuries and one person suffered suspected life-threatening injuries.
The eastbound lanes were closed between Union Road and Colonel Talbot Road for several hours.
Anyone who may have witnessed the crash is asked to call the OPP at 1-888-310-1122 or contact the nearest police authority.
