Provincial police are investigating a fatal collision involving three tractor trailers on Highway 401 eastbound near Guelph, Ont.

The collision occurred just after 3 a.m. on Saturday when a tractor trailer rear-ended another tractor trailer on Hwy. 401, near Hwy. 6 south in Wellington County.

Upon being hit, police said the truck veered out of control and struck a third tractor-trailer in a lane to its right.

Police said the driver of the third truck became trapped in his vehicle. He was pronounced dead on scene.

The victim was a 38-year-old man from Brampton, Ont., OPP Sgt. Dave Woodford told CTVToronto.ca. His name has not yet been released.

Woodford said the female driver of the first truck was transported to hospital with minor injuries. The driver of the second truck wasn't hurt, he said.

Police have closed all but one of Hwy. 401's eastbound lanes at Hwy. 6 south for investigation. The lanes are expected to re-open around noon.

Anyone who may have witnessed the accident is encouraged to call Ontario Provincial Police at 519-654-0150.