A warning system on the Delta Air Lines flight that crashed at Pearson airport last month sent an alert indicating a high rate of descent less than three seconds before the plane touched down, according to a preliminary report.

A preliminary report into the Delta Air Lines flight that flipped upside down in a crash landing at Toronto's Pearson International Airport last month shows the plane had been descending at a high rate of speed. Twenty-one people were injured in the botched landing on Feb. 17.