A serious collision between a motorcycle and a transport truck has shut down all eastbound express lanes on Highway 401 in Scarborough.

The crash, which occurred around 4:30 p.m. between Kennedy and Brimley roads, has left the motorcycle rider with serious, life-altering injuries. The rider was transported to the hospital by paramedics.

Ontario Provincial Police have confirmed the closure, and the cause of the collision is still under investigation.