IndyCar chief executive Randy Bernard later confirmed at a press conference that Wheldon had died as a result of “unsurvivable injuries”.

Wheldon’s fellow drivers got in their cars to perform a five-lap salute in his honour and figures from the world of motor racing were quick to pay tribute to the 2005 IndyCar series champion.

Hamilton, the 2008 Formula One world champion, said: “This is an extremely sad day. Dan was a racer I’d followed throughout my career, as I often followed in his footsteps as we climbed the motorsport ladder in the UK.

“He was an extremely talented driver. As a British guy, who not only went over to the States but who twice won the Indy 500, he was an inspirational guy, and someone that every racing driver looked up to with respect and admiration.

“This is a tragic loss at such a young age. My heart goes out to his family and friends during this extremely difficult time.”

A number of cars came into contact on turn two, sending several of them flying through the air, smashing into the outside wall and catch fence.

With cars smouldering and debris littering the track, the race was red-flagged as crews worked on fences and removed the damaged cars.

Two-time Indianapolis 500 winner Wheldon had been in line to win $5m had he won the race.

Bernard added: “Our thoughts and prayers are with his family today. IndyCar, its drivers and team owners has decided to end the race. In honour of Dan Wheldon, the drivers have decided to do a five-lap salute in his honour.”

Scotsman Dario Franchitti – who was yesterday confirmed as the IndyCar 2011 champion – insists warning signs were there.

“I could see within five laps people were starting to do crazy stuff,” Wheldon’s former Andretti Green team-mate, who was not involved in the crash, told IndyCar.com. “I love hard racing but that to me is not really what it’s about. One small mistake from somebody...”

He added: “Right now I’m numb and speechless. One minute you’re joking around in driver intros and the next he’s gone. He was six years old when I first met him. He was this little kid and the next thing you know he was my team-mate.

“We put so much pressure on ourselves to win races and championships and today it doesn’t matter.”

Buckinghamshire-born Wheldon, a father of two who lived with his wife and sons in Florida, won 16 times in his IndyCar career and was the series champion in 2005.

Wheldon started at the back of the 34-car line-up but quickly started to make his way through the field before the pile-up, which injured three other drivers.

His colleagues were reportedly told of his death around two hours after he was airlifted from the Las Vegas Motor Speedway track to University Medical Center.

Wheldon becomes the first IndyCar fatality since American rookie Paul Dana was killed in a practice session five years ago.