One woman had to be cut out of the wreckage of her car after a two-vehicle crash closed the intersection of Hwy. 48 and Park Road near Sutton.
The crash, which happened at about noon, also sent two other people to hospital.
The injuries are described as serious.
OPP have since re-opened the northbound lanes, but the southbound lanes remain closed as the collision between the car and minivan is investigated.