This video shows the wreckage of one of the planes in the parking lot.
"The person who was seriously injured was a pilot, and the death was the other pilot", she said.
Witnesses at the scene described hearing a loud bang.
The mall was evacuated shortly after the crash when officers noticed kerosene from the plane leaking through the roof of the mall.
Rene Thibault said he was in another of the mall's parking lots when he heard a loud cracking sound.
The regulatory board said in a statement that both planes were Cessna 152 aircraft operated by Cargair, a pilot-training academy based in nearby Longueuil.
Martinez said he ran to the plane and saw a man inside, whose body was crushed. "Then we saw pieces of plane fall out of the sky everywhere".
Police were talking to witnesses about the incident and had reportedly cordoned off the area.
The Transportation Safety Board of Canada announced it was deploying a team of investigators to the site.
She added the federal agency will also talk to every witness of the crash. The website for the flight school was unavailable.
Cargair said in a news release it was working with authorities and offered its sympathies to the families of the pilots.
May 12, 2012: Four adults and an 11-year-old boy are killed near St. Brieux, Sask., when a small plane heading to a northern fishing camp collides with a plane travelling from Alberta.
In that 1997 crash both planes were approaching the runway to land.