A man is dead after a multi-vehicle crash in the eastbound express lanes of Highway 401 east of Avenue Road, paramedics confirm.

Three other people suffered non-life-threatening injuries in the crash, which involved nine vehicles including a dump truck which rolled over onto a car.

All eastbound express lanes were closed from Allen Road to Highway 404 for almost 12 hours. They re-opened just before 3 a.m., 680News Traffic reports.

“There’s nine vehicles involved, they’re all throughout the scene across all lanes of traffic,” OPP Sgt. Kerry Schmidt explained. “There’s one large commercial dump truck that’s on its side.”

Police believe the dump truck driver lost control for unknown reasons, hitting several other cars before rolling over spilling its contents onto the roadway.

Schmidt says the contents of the truck, which appeared to be a type of sand, covered one of the cars completely. The driver inside the car was pronounced dead at the scene.

The investigation is ongoing.