Summarize this content to 2000 words in 6 paragraphs Conditions were clear following days of extreme snowfall at Toronto Pearson International Airport when a Delta plane carrying 80 people flipped upside down in a fiery crash-landing, officials said, prompting questions about what caused the plane to overturn on the runway in another nightmare scenario for air travelers.In the days leading up to the incident, two storms dropped more than 20 inches of snow at the airport, which is more snow accumulation than the airport saw all of last winter, Toronto Pearson President and CEO Deborah Flint said at a news conference Tuesday.“Monday was a clear day, though,” Flint said, adding that it was an “operational recovery day” for the airport after the pair of storms canceled nearly 800 scheduled flights.Yet, when Delta Flight 4819 came in for a landing from Minneapolis-St. Paul International Airport around 2:15 p.m. Monday, it burst into flames upon landing and turned upside down on the tarmac, leaving 76 passengers and four crew members dangling from their seat belts, according to witnesses and a video posted on social media.“All of a sudden, I just remember being fully sideways,” passenger Pete Koukov said on the “TODAY” show Tuesday morning. “I was looking down and just seeing like sparks and flames and whatever was grinding against the ground. It happened pretty dang quick and we were just upside down, hanging from our seat belts.”There were no deaths, and none of the 21 people treated at local hospitals had life-threatening injuries, Flint said. Nineteen of them have since been released, she said. Another official at the news conference said the injuries were mostly back sprains, anxiety, head injuries and headaches, as well as nausea and vomiting due to fuel exposure. Flint said the cause of the crash is being investigated by the Transportation Safety Board of Canada, as she urged against speculation and declined to answer questions about the conditions of the runway.On Monday, Todd Aitken, fire chief with the Greater Toronto Airports Authority, told reporters that the runway was dry and that there were no crosswind conditions. At the Tuesday news conference, Aitken directed questions about the investigation to the TSB.The incident comes after two back-to-back deadly aircraft crashes in the U.S. sparked concerns about flying. Seven people were killed in Philadelphia on Jan. 31 after an air ambulance careened out of the sky and crashed near a mall. Two days before that, an Army helicopter and a commercial airplane collided midair near Washington, D.C., killing all 67 passengers in both aircraft, in the deadliest U.S. air crash in almost a quarter century. There is still no official cause for either crash, though the National Transportation Safety Board, which is investigating both cases, said Friday that it had more work to do regarding the Washington, D.C., crash.
