TORONTO — Delta Air Lines is offering US$30,000 (£23,792) to each person on board a plane that crash-landed in Toronto on Monday - all of whom survived.

As it landed in the Canadian city, the plane skidded along the runway in flames before flipping over and coming to a halt upside down. Passengers described their amazement as most of them walked away without injuries.

It remains unclear what caused the incident, which is under investigation.

There were 76 passengers and four crew on the flight, which had traveled from the US city of Minneapolis before making its crash-landing in Canada.

A spokesperson for Delta said the money offer had no strings attached and did not affect customers' rights.

The plane crew and emergency responders were praised for their quick work in removing people from the wrecked vehicle. The plane's various safety features have also been credited for ensuring no loss of life.

All but one of the 21 passengers who were taken to hospital had been released by Wednesday morning, the airline said.

Delta's chief told BBC's US partner CBS News that the flight crew were experienced and trained for any condition.

The airline's head Ed Bastian told CBS the plane crew had "performed heroically, but also as expected", given that "safety is embedded into our system". He said Delta was continuing to support those affected.

Several theories about what caused the crash have been suggested to the BBC by experts who reviewed footage, including that harsh winter weather and a rapid rate of descent played a role.

One passenger recalled "a very forceful event", and the sound of "concrete and metal" at the moment of impact. Another said passengers were left hanging upside down in their seats "like bats".

The cockpit voice recorder and flight data recorder have been recovered from the wreckage. The investigation is being led by Canada's Transportation Safety Board (TSB), supported by US officials.

The accident was the fourth major air incident in North America in a space of three weeks - and was followed on Wednesday by a crash in Arizona in which two people lost their lives when their small planes collided.

Experts continue to insist that air travel is overwhelmingly safe - more so than other forms of transport, in fact.

That message was emphasized by US Secretary of Transportation Sean Duffy, who told CBS on Wednesday there was no pattern behind the incidents, each of which he said was "very unique". — BBC