One person is dead after a crash on Highway 401 in Milton, Ont., on Wednesday evening.

The collision happened east of Guelph Line at approximately 5:30 p.m.

OPP Const. Ian Michael said one of the drivers exited his vehicle after the collision and was struck by a passing SUV.

"For unknown reasons, the male driver … was outside of his vehicle when he was struck by an Acura SUV," Michael told CTV Toronto, speaking at the scene of the crash.

The driver was transported to a local hospital where he was pronounced dead.

Michael said the driver of the Acura SUV stayed on scene after the crash and is cooperating with police.

The eastbound lanes of Hwy 401 at Guelph Line were temporarily closed as police investigated the crash. The lanes reopened shortly after 9:30 p.m.