Feb 18 (Reuters) - Delta Air Lines ( DAL ) said on

Tuesday that 19 out of the 21 passengers transported to local

hospitals after a Toronto plane crash a day earlier have been

released, as officials continue a probe into why the regional

jet flipped over upon landing.

Investigators from Canada's Transportation Safety Board

(TSB) are leading the probe into why the CRJ900 aircraft

operated by Delta Air Lines' ( DAL ) Endeavor Air subsidiary went

belly-up on Monday at Toronto's Pearson Airport.

It's not yet clear what happened to Flight DL4819 from

Minneapolis-St. Paul International Airport. Air crashes are

usually caused by multiple factors.

The 16-year-old CRJ900, made by Canada's Bombardier

and powered by GE Aerospace engines, can seat

up to 90 people. At least one of the two wings was no longer

attached to the plane, video showed after the accident.

Toronto Pearson Airport said earlier on Monday it was

dealing with high winds and frigid temperatures as airlines

attempted to catch up with missed flights after a weekend

snowstorm dumped more than 22 cm (8.6 inches) of snow at the

airport.

The Delta plane touched down in Toronto at 2:13 p.m. (1913

GMT) after an 86-minute flight and came to rest near the

intersection of runway 23 and runway 15, FlightRadar24 data

showed.

The weather at the time of the crash indicated a "gusting

crosswind and blowing snow," the flight tracking website said.