The plane went down on Highway 20 shortly after take-off, just before 12 p.m. ET.
Quebec provincial police Sgt. Ronald McInnis said the plane flipped once and landed on the roadway.Two people on board the plane suffered serious injures, but police say their lives are not in danger.
Investigators are on the scene to find out exactly what caused the crash.
The westbound lane of the highway was closed for several hours as emergency workers removed debris.