Dan Wheldon, 33, a world­-renowned race-car driver whose victory this year in the Indianapolis 500 had made him a two-time winner of one of the best-known events in auto racing, was killed Sunday in a crash at an event in Las Vegas.

According to news accounts, the fatal crash occurred as Mr. Wheldon was taking part in the 2011 Izod IndyCar Series season finale at the Las Vegas Motor Speedway.

Minutes into the race, he became enmeshed in a fiery 15-car pileup and had to be pulled from the wreckage of his vehicle. He was flown to a hospital but later died. According to the Associated Press, the race was stopped.

On May 30, Mr. Wheldon had known the delight of his second victory in the grueling 200-lap competition at the Indianapolis Motor Speedway, one of the world’s shrines of auto racing, a venue steeped in the smell of motor fumes and the reek of burning rubber.

“I’m just extremely happy,” Mr. Wheldon said then, only minutes after he had moved into first place at the end of the race. “To think that I’m a two-time winner . . .

Mr. Wheldon’s first win in the 500 had come in 2005. In May, as this year’s 500 roared to a close, it appeared that a second victory for Mr. Wheldon in the legendary event would have to wait. Another driver, JR Hildebrand, was in first place with 1,000 yards to go.

But disaster struck as Hildebrand neared the finish line. His car smashed into the outside wall, and Mr. Wheldon moved into first place for the first time that day. He crossed the finish line a winner. It was a signal accomplishment in a race that traces its history to 1911.

Mr. Wheldon’s reactions in the succeeding minutes were recounted in USA Today:

As soon as he recognized that Hildebrand’s crash had not caused serious injury, “there was a little smile on my face,” Mr. Wheldon said.

“From that point, it was just making sure that I didn’t do anything silly,” he said. “Then I think I got on the radio and started crying.”

For Mr. Wheldon, the win, plucked from the jaws of defeat, was much needed. It was said to be his first since 2008. His contract with one car-racing group was expiring, and there was no assurance when he got behind the wheel that day that he would have a vehicle to drive for the rest of the year.

A specialist in what is known as open-wheel racing, he had won more than a dozen other events and was regularly ranked in the top 10 in the yearly IndyCar racing standings. (Open-wheel cars have wheels outside their bodies in contrast to NASCAR vehicles, which more closely resemble cars driven on the streets.)

This year’s Indy win may have been the peak of a career that had been concerned with driving and racing since Mr. Wheldon’s boyhood in his native England.

Daniel Clive Wheldon was born in Emberton, in Buckinghamshire, on June 22, 1978. He was said to have started driving karts at age 4, and he continued to drive open-wheeled cars in competitions into his teen years in Britain.

Ultimately recognizing that serious racing took more money than he or his family could provide, he left for the United States. After three years at lower levels of IndyCar competition, he ascended to the big time in 2002 and was recognized the next year as the top newcomer in the IndyCar Series.

Although sponsorships were not always easy to obtain, even in the United States, Mr. Wheldon was devoted to the sport. This single-mindedness apparently caused him occasional problems.

“I put everything into my racing, and I expect the same back,” he was quoted as saying. “If I see people who aren’t giving it, I’m not afraid to say so, but that sometimes comes out a little brash. That could be improved a little bit.”

At Indianapolis, racecars regularly reach speeds of 200 miles an hour, covering about the distance of a football field in a single second. Drivers require exceptional skill, and Mr. Wheldon was much admired for his ability on the track. Fans also praised his friendliness to them away from competition.

Among his achievements were two second-place finishes in the 500, in 2009 and 2010.

But he also had rough patches in his career, and in what seemed a bit of racing irony, he was replaced at one point as a driver for the Panther Racing organization by Hildebrand, whose crash at Indy this year enabled Mr. Wheldon to win.

Mr. Wheldon, who lived in St. Petersburg, Fla., was married and had two children.

He was interested in photography and released a book of photos of his career, which included many pictures of his wife. He wanted those in there, he told the Associated Press. “She was the most beautiful bride on her wedding day the world had ever seen.”