Dramatic new footage released on Tuesday showed a passenger plane hitting the runway hard and flipping upside down at Toronto's airport, as investigations began into the cause of the crash.

A fire ball and thick plumes of black smoke engulfed the Delta Air Lines plane as it skidded to a halt on its roof on Monday but none of the 80 people on board were killed.

"The crew of Delta Flight 4819 heroically led passengers to safety, evacuating a jet that had overturned on the runway on landing, amidst smoke and fire," Toronto airport authority chief executive Deborah Flint told a news conference.

She said Canada's Transportation Safety Board has deployed 20 investigators to the site where the Bombardier CRJ-900 crashed.

They will be assisted by the US Federal Aviation Administration and representatives from Delta and Mitsubishi, which purchased this line of planes from Bombardier in 2019.

Injuries sustained in the crash ranged from "minor to critical, but not life-threatening," Flint said.

Delta said 21 passengers were transported to hospitals and so far 19 have been released.

Paramedic services told AFP on Monday that three people had been critically injured — a child, a man in his 60s and a woman in her 40s.

The flight with 76 passengers and four crew was landing in the afternoon in Canada's largest city after a flight from Minneapolis in the US state of Minnesota.

Todd Aitken, the airport's fire chief, said late Monday it was too early to determine the cause of the crash.

"It's really important that we do not speculate. What we can say is the runway was dry and there was no crosswind conditions," he said.

Black smoke

The video posted to social media and verified by AFP was taken from the cockpit of another jetliner waiting on the tarmac.

It showed the plane coming in for a normal landing before slamming into the runway, then sliding forward in a roll to the right, with its wings sheared off before it stopped on its back.

Flames could be seen shooting out of the fuselage and black smoke billowing out.

"Oh no no no no no," the pilot is heard saying in the video that was laced with expletives.

Rescue services responded, spraying water at the jet, whose underside was scraped and blackened.

Aitkin said rescue teams saw isolated fires when they got to the scene.

"They were able to quickly knock down the spot fires" and enter and search the plane, he told reporters Tuesday.

Most of the passengers had already "self evacuated," he added.

Corey Tkatch of the area's paramedic services said emergency responders dealt with a "multitude of different injuries" including back sprains, head injuries, anxiety, and headaches.

Passengers reported smelling jet fuel as they exited the plane. Some suffered from nausea and vomiting due to the fuel exposure, he said.

In the days prior to Monday's crash, two massive snowstorms hit eastern Canada, dumping 70 centimeters (more than two feet) of snow, which Flint said was "more snow than we received in all of last winter."

Strong winds and bone-chilling temperatures could still be felt in Toronto on Monday when airlines added flights to make up for weekend cancellations due to the storm.

The Toronto crash was the latest in a recent string of air incidents in North America, including a mid-air collision between a US Army helicopter and a passenger jet in Washington that killed 67 people, and a medical transport plane crash in Philadelphia that left seven dead.