TORONTO — Four people from the Greater Toronto Area died after a single-vehicle crash in rural Puslinch early Saturday, when their vehicle left the road, struck a guardrail and fell into a ravine.Ontario Provincial Police said the collision happened around 1:35 a.m. on Oct. 31 on Watson Rd. S., between Maltby Rd. E. and Wellington Rd. 34, southeast of Guelph. Of the six occupants that were in the vehicle, four were pronounced dead at the scene.The deceased are a 19-year-old man from Mississauga, a 19-year-old man from Brampton, a 17-year-old girl from Mississauga and a 15-year-old girl from Milton, according to Wellington County OPP Insp. Karen Medeiros, who spoke at a news conference Sunday in Rockwood. “This is a devastating event that has impacted multiple families, schools, friend groups and communities across southern Ontario,” Medeiros said at the Sunday briefing, calling the crash an “unimaginable tragedy.”Two other girls from Mississauga survived and were taken to hospital. A 17-year-old remains in hospital with life-altering injuries. A 16-year-old has non-life-threatening injuries. None of the victims have been named.Investigators are examining all available evidence, including speed and seatbelt use. Medeiros said she does not believe the vehicle had enough seatbelts for the six occupants. Police have not yet determined whether the driver was among the deceased, where the group was travelling from or to, or whether alcohol or drugs were factors.Police are asking anyone with information, dashcam footage, or surveillance video from the area around the time of the crash to contact Wellington County OPP at 1-888-310-1122.