Two people suffered life-threatening injuries following a multi-vehicle crash on the northbound portion of Highway 400 in King City, Ontario.

The Ontario Provincial Police (OPP) said It happened around 10:30 pm Monday, just north of King City ONRoute.

Provincial police said a transport truck and a blue Toyota had slowed in the construction zone when a third vehicle crashed into the rear of the Toyota, causing it to collide with the rear of the truck.

OPP said the two injured people were in the Toyota and charges are pending against the driver of the third vehicle. Investigators believe speed and distraction were factors in the crash. No other injuries were reported.

Northbound lanes remain blocked from Teston to King, and the OPP expects this section to remain closed until approximately 8 a.m. Tuesday.

Members of the OPP Aurora detachment are investigating. Anyone with dash cam footage or information is asked to come forward.