Canadian investigators said on Tuesday they recovered the so-called black boxes from a regional jet that flipped upside down upon landing in windy conditions a day earlier at Toronto's Pearson Airport, injuring 21 of the 80 people on board.

Investigators from Canada's Transportation Safety Board are leading the probe to figure out why the CRJ900 aircraft operated by Delta Air Line's Endeavor Air subsidiary went belly up on Monday at Toronto's Pearson Airport, the country's largest airport.