An investigation is underway into the Delta plane that crash-landed Monday in Toronto. What caused it remains to be seen, but here's what we know so far.

All 80 people aboard the Delta plane that flipped upside down and crash landed in Toronto survived, but three, including a child, are critically injured.

Investigators are looking into how all 76 passengers and four crew members aboard Delta Air Lines Flight 4819 survived after the plane crash-landed in Toronto on Monday.