A multi-vehicle crash on Highway 400 south of Highway 88 killed one person, sent four others to hospital and shut down the highway's southbound lanes for four hours on Monday.
One person was taken to hospital via air ambulance.
The OPP say the crash happened just after 7 a.m. Monday on slick roads. The highway wasn't reopened until after 11 a.m.
The crash also affected northbound traffic, with only one lane open in that direction for a few hours on Monday.
The cause of the crash is under investigation.