OPP closed the westbound lanes of Highway 403 on Tuesday morning after a pedestrian was reportedly struck by a tractor trailer.
Police say the collision happened around 8:30 a.m. and closed the highway from Wayne Gretzky Parkway to King George Road.
The male pedestrian was taken to a local hospital by paramedics then airlifted for treatment of life-threatening injuries.
OPP say the driver of the westbound tractor trailer remained on scene and is cooperating with police.
OPP Traffic Collision Investigators are assisting with the investigation.
The highway was reopened shortly after 2 p.m.
Anyone who witnessed the collision or who may have information is asked to contact OPP at 1-888-310-1122.
#BrantOPP on scene for collision investigation on #HWY403 w/b lanes west of Wayne Gretzky Pkwy. Male pedestrian struck by a w/b tractor trailer. #HWY403 closed between Wayne Gretzky Pkwy and King George Rd. #OPP asking witnesses to call 1-888-310-1122 with any information. ^rl pic.twitter.com/D7mxjQh7td— OPP West (@OPP_WR) July 2, 2019