Ontario Provincial Police say Highway 400 is closed at Rutherford Road.
Sgt Kerry Schmidt reports via the official Twitter account of the Ontario Provincial Police, Highway Safety Division, that traffic is being turned around.
"Around 8:45 p.m. (we were called to) a serious collision involving multiple vehicles (headed) southbound on Highway 400 near Rutherford Road," reports Schmidt.
All southbound lanes of the highway are closed at Rutherford Road, and Schmidt describes the collision as very serious, maybe even grave.
He also says the closure between Highways 88 and 9 is still in force.
"The 400 is not an option for any practical purposes anytime, anywhere right now," Schmidt adds.
One vehicle involved in the crash was completely consumed by fire and two people were taken to hospital by ambulance, he said.
One person was critically injured.
