Officials say a blast of winter weather that included damaging winds and blowing snow caused chaos on highways in southern Ontario and left thousands of people without power.
A major crash on Highway 400 near Barrie left several people with minor injuries.
Local fire officials say the collision involved more than 70 vehicles and required a stretch of the highway to be shut down in both directions.
Ontario Provincial Police Sergeant Kerry Schmidt says driving conditions in the area were terrible. He says there are whiteout conditions with snow and blowing snow and zero visibility.
Videos of the collision posted by Schmidt online show dozens of vehicles, including several transport trucks and one fuel tanker, smashed together, with numerous cars also in the ditch.
Schmidt says the fire department had to use the Jaws of Life to pry some of the vehicles apart.
Samantha Hoffman, a spokeswoman for the Barrie fire department, says a 500-litre diesel spill caused by the crash is under control.
Authorities were dealing with other multi-vehicle pileups in other parts of Ontario.
Provincial police in eastern Ontario say an 18-vehicle collision in Champlain Township sent seven people to hospital, some with serious injuries.
There were no serious injuries in a 20-car pileup on Highway 11 near Orillia nor was anyone seriously hurt in a 14-car crash on Highway 115 near Peterborough.
High winds that swept across parts of the province late Sunday into Monday also left thousands without power.
Hydro One said more than 175,000 people lost electricity in the nearly 24 hours since the storm hit.
Spokeswoman Alicia Sayers says the utility has restored power to the majority of customers.
