The 33-year-old Englishman died from injuries he received after he became caught up in the grisly pile-up, his car spinning into the catch fenching around the track.
Several cars were sent flying while others careered down the track in flames, littering the track with smoking debris.
“IndyCar is very sad to announce that Dan Wheldon has passed away from unsurvivable injuries,” IndyCar chief executive Randy Bernard said.
“Our thoughts and prayers are with his family today.”
Wheldon’s fellow drivers had been informed of his death shortly before Bernard made his announcement.
“IndyCar, its drivers and owners, have decided to end the race. In honor of Dan Wheldon, the drivers have decided to do a five-lap salute in his honor,” Bernard said.
The crash started at Turn 2 of the 1.5-mile (2.4-kilometer) Las Vegas oval on the 12th lap of the race.
The chain-reaction appeared to begin when Wade Cunningham’s car swerved and J.R. Hildebrand drove over Cunningham’s car. Hildebrand went airborne while Cunningham went into the wall.
“It was debris everywhere across the whole track, you could smell the smoke, you could see the billowing smoke on the back straight from the car,” said Danica Patrick, who was in her final race as a fulltime IndyCar driver before heading to NASCAR stock car racing.
“There was a chunk of fire that we were driving around. You could see cars scattered,” added Patrick, who was among the drivers who predicted a chaotic race given the high speeds in qualifying and the jam-packed 34-car field.
Wheldon, traveling behind the cars that initiated the chaos, couldn’t avoid the crashes in front of him.
“I saw two cars touch each other up in front of me and then I tried to slow down, couldn’t slow down,” Canadian Paul Tracy said. “Then Dan’s car, from what I saw in the videos, came over my back wheel and over top of me. Just a horrendous accident.”
Tracy had reported that a medical team was frantically attending Wheldon before the driver was airlifted to hospital.
The official confirmation of his death came some two hours after the race was stopped.
Despite two Indianapolis 500 triumphs — including this year’s race in May — and his 2005 series title, Wheldon hadn’t been able to secure a full-time IndyCar ride this season, so he was racing from the back of the field in pursuit of a $5 million prize offered by IndyCar to a non-series driver who could win the finale.
The crash ended Australian Will Power’s bid to overtake Dario Franchitti and claim the series title.
Power sat stunned in his car for some time and was later sent to hospital to be checked out because of back pain.
Hildebrand and Pippa Mann were also hospitalized. Mann was treated for a burn on her right hand while Hildebrand was said to be awake and alert but under observation after complaining of dizziness.
“I’ll tell you, I’ve never seen anything like it,” Ryan Briscoe said. “The debris we all had to drive through the lap later, it looked like a war scene from ‘Terminator’ or something.”
IndyCar’s last previous fatality was the death of driver Paul Dana at the Homestead circuit in Florida in 2006 in a crash during pre-race practice.
Scotland’s Franchitti, who secured his third straight series crown and fourth overall, could be seen weeping and fighting for composure in his cockpit as the drivers formed up for the tribute laps — with Wheldon’s number 77 the only one displayed on the giant scoreboard tower.
Wheldon, who moved to the United States in 1999, got his first IndyCar series ride in 2002 and his first victory the next season.
In 2005, he became the first Englishman since the great Graham Hill in 1966 to win the Indianapolis 500.
This year at Indianapolis he was racing a distant second to Hildebrand, who lost control and nipped the wall on the last lap, allowing Wheldon to speed past for another triumph at the Brickyard.
At the traditional post-race photo opportunity, Wheldon was joined by his two-year-old son Sebastian and his wife, Susie, who held their son Oliver, who was then two months old.
“What can you say? We’re going to miss him,” said Chip Ganassi, a team owner Wheldon once drove for. “Everybody in IndyCar died a little today.”