(CNN) -- Two-time Indianapolis 500 winner Dan Wheldon died Sunday of "unsurvivable injuries" sustained during a multi-car wreck at the Las Vegas Indy 300. He was 33.

Photo Gallery: IndyCar driver Dan Wheldon dies in 15-car crash

The rest of the race -- the marquee event of the IZOD IndyCar World Championships -- was canceled, said IndyCar CEO Randy Bernard. The drivers, many of whom were visibly emotional after emerging from a meeting with IndyCar officials, did a five-lap salute in Wheldon's honor.

"Amazing Grace" played as the drivers slowly wound their way around the track.

"IndyCar is sad to announce that Dan Wheldon passed away from unsurvivable injuries. Our thoughts and prayers are with Dan and his family," Bernard said.

More than a dozen vehicles were involved in Sunday's fiery wreck. Video of the accident showed cars spinning out of control, bursting into flames, and shooting smoke and debris into the air.

Championship contender Will Power and Rookie of the Year candidate J.R. Hildebrand were also involved in the crash, according to the official Twitter page of the IZOD IndyCar Series.

Wheldon was in line to win $5 million if he had captured the checkered flag at Sunday's race.

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"He was a great champion of the Indianapolis 500 and a wonderful ambassador for the race, the Indianapolis Motor Speedway and all of motorsports," Indianapolis Motor Speedway Corporation President and CEO Jeff Belskus said in a statement.

"Most importantly, he was a fantastic husband, father and man -- a good friend to so many in this sport. His memory will live forever at the Speedway, both through the magnitude of his accomplishments on the track and his magnetism off the track," he said.

Racing accidents are not uncommon, though fatal ones have been rare in recent years.

Safety improvements at such high-speed events have included the installation of "soft walls." So-called SAFER barriers, which include foam, are intended to soften the effects of impact. Other equipment protects a driver's head during impact.

In 2006, driver Paul Dana died in a two-car collision during a practice run at Homestead-Miami Speedway in Florida.

Driver Tony Renna died in October 2003 of injuries suffered in a testing accident at Indianapolis Motor Speedway, while Scott Brayton was killed at the same speedway in May 1996 when his vehicle hit the wall during practice.

After his second Indy 500 victory in May, Wheldon talked with CNN's "American Morning" about the intensity of the race track. He first win was in 2005.

"We're doing speeds in excess of 225 miles per hour. With this race, you never know what can happen. It's about staying focused and you really don't ever let off the power unless you have to," he said.

Wheldon, who was born in Emberton, England, lived in St. Petersburg, Florida. His father was a go-kart racer and his mother was the timer at a local track. Wheldon is survived by his wife and children.

CNN's Phil Gast and Jason Durand contributed to this report.