Four young men were killed and two others were sent to hospital after a head-on crash north of Collingwood on Friday.
Ontario Provincial Police say the crash happened on Highway 26 east of Meaford in the early afternoon.
The four people killed are all teenagers from the Town of Blue Mountains and all attended Georgian Bay Secondary School, police told RadioOwenSound.com.
They victims were identified as Michael Fleming, Drew Perry and Andrew McKean, all 16 years old, and 17-year-old Morgan Fitzgerald. Reports suggest they were heading to a hockey tournament.
Another passenger in the vehicle, 17-year-old Michael O'Hara, was critically injured in the crash and taken to Sunnybrook Hospital in Toronto. He too is from Blue Mountains and attends the same high school.
The driver of the other vehicle was identified as Rodney Gibbons, 60, of Meaford. He was taken to a local hospital with unknown injuries.
Police said the crash occurred when the SUV carrying the teens crossed into the westbound lane as it was travelling east on the highway. The vehicle was then struck by a cargo van.
The SUV left the road and landed into the ditch. The impact caused some of the teens to be ejected from the vehicle. It was not clear if they were wearing seatbelts.
The impact littered the roadway with debris, and the SUV's sunroof was found 12 metres up a nearby tree, police said.
Three victims were pronounced dead at the scene, while the fourth died later in hospital.
The highway was still closed late Friday night as police investigated.