A mechanical problem seems to have caused an airplane crash on Highway 401 near Bainsville Monday evening. Two occupants in the Cessna 150 were injured when the plane crashed in the median of 401 near the Fourth Line Road in front of the Bainsville ONRoute station just before 8:15 p.m. One occupant was airlifted to hospital by Ornge with life-threatening injuries and the second occupant was transported to hospital by ambulance with non-life threatening injuries. Initial investigation indicates the airplane may have experienced a mechanical problem after departing from the Valleyfield airport. The airplane struck hydro wires prior to landing in the centre median on Highway 401, says the Stormont-Dundas-Glengarry Ontario Provincial Police detachment. The Transportation Safety Board of Canada is assisting with the investigation. A section of the highway had been closed for several hours.