Two small planes collided over a bustling shopping mall south of Montreal, killing one person and injuring three others, said Quebec's public security minister Martin Coiteux.
Police in the city of Longueuil, Quebec, said each plane only had a pilot on board and that both were injured.
"One of the planes crashed on the roof of one of the stores and the other one on the asphalt of the parking lot," said Nancy Colagiacomo, a spokeswoman for the police force that serves Montreal's south shore.
A security perimeter was set up near the shopping centre yesterday.
Witnesses at the scene described hearing a loud bang.
Nheil Martinez, who works inside the mall, was outside smoking a cigarette when he says he saw the shadow of a plane and heard its motor.
"I heard the motor so low to the ground and then a loud boom," he said.
"Then we saw pieces of plane fall out of the sky everywhere."
Martinez said he ran to the plane and saw a man inside, whose body appeared to be crushed.
Jonathan Vanasse, who was eating inside a mall restaurant next to the crash site, said he and several others ran outside and saw a plane, which he said was leaking fuel.
He said all that was left of the aircraft was shredded metal.
The Transportation Safety Board of Canada has sent a team of investigators to the site. It said both planes were Cessna 152 aircraft operated by Cargair, a pilot-training academy based in nearby Longueuil.