Bob Parsons, the CEO of Internet domain name registrar GoDaddy, which sponsored the IndyCar Challenge that cost Dan Wheldon his life Sunday, has commented on the tragedy.

"Our thoughts and prayers go out to Dan Wheldon's family and friends on this sad, sad day. All of us in the IndyCar Series family feel an unexplainable sense of loss. Not just for the sport, but for all who knew Dan Wheldon. Dan was a family man, a father, a husband, a son and a brother. The two-time Indianapolis 500 winner was also a competitor and a colleague ... our deepest condolences go out to all who knew Dan," Parsons said in an official statement.

Wheldon, 33, died following a horrifying accident on Sunday at Las Vegas Motor Speedway. The accident occurred when his car flew mid-air and burst into flames after a 15-car pileup. He was immediately airlifted to a local hospital but died there. Three others were injured in the pileup.

Wheldon, who won the 2011 Indianapolis 500, had competed in only two events so far this year. He was offered a $US5 million promotion called the GoDaddy IndyCar Challenge, which was aimed at luring race drivers who did not compete in the series full-time.

"I am really excited to return in the No. 98 entry with [racing teams] SSM and BHA, to follow up our success at this year's Indy 500 and to go after another race win, especially with this carrot on the end of the stick," Wheldon said before the race.

"I actually met Go Daddy CEO and founder Bob Parsons the morning of this year's Indy 500, so maybe he's my lucky charm? I'm ready for the Go Daddy IndyCar Challenge and, hopefully, myself and one lucky fan will be smiling on Oct. 16."

GoDaddy's prize money was up for a 50:50 split with a lucky fan. Wheldon had to win the race to collect the $US5 million.

Wheldon is survived by his partner Susie Behm, with whom he had two sons - Sebastian, 2, and Oliver, seven months.