Police closed a section of Highway 7 in Stratford on Tuesday as they investigated a serious collision.

The crash occurred around 5 p.m., at the intersection of the highway – also known as Erie Street – and Lorne Avenue.

It involved a transport truck and a sedan, both of which ended up in a ditch along the road.

According to police, witnesses say the sedan was travelling northbound when it crossed into the southbound lanes. Police say the driver of the truck was unable to avoid the collision.

A spokesperson for Ornge said that one man in his 20s had been airlifted to a London hospital in critical condition. The driver of the truck did not suffer any injuries.