The OPP said the two right lanes of the southbound Hwy. 400 remain closed near the area where it becomes Black Creek Drive — just south of Hwy. 401 — as investigators try to figure out what went wrong.
Police on scene told the CBC's Tony Smyth that the person who was killed may have been out of their vehicle when it was struck. The vehicle had been pulled over to the shoulder when the collision occurred before 5 a.m.
It's not clear when the closed lanes will reopen at this time.