A major accident has closed Highway 158 near St-Alexis in Quebec's Lanaudière region.
Police say the head-on collision happened just after 7 a.m, about 60 kilometres north of Montreal.
A third vehicle then drove off the road.
Four people are injured and one of them is in critical condition.
Police had to use the Jaws of Life to get one person out of a vehicle.
They say it's unclear when they will be able to reopen the highway.