A fiery crash sent Kyle Larson's car flying and debris spinning into the stands injured dozens of race fans Saturday at the NASCAR stock car Nationwide Series season-opener.
Joie Chitwood, president of Daytona International Speedway, said 28 spectators were injured -- 14 taken for treatment at local hospitals and 14 more treated at the track's medical facility.
He said he could not confirm reports that at least two people were seriously hurt.
"It's not appropriate for me to comment on that," Chitwood said in a press conference held at the circuit some three hours after the wreck.
Various media reports put the number of injured at more than 30, with ESPN reporting that one adult had head trauma and a 14-year-old also suffered critical but not life-threatening injuries.
The wreck occurred almost as Tony Stewart was taking the chequered flag for victory and began when Regan Smith, trying to block to preserve his lead, was turned sideways and a dozen cars bunched behind him.
Larson, a Japanese-American driver who was making his first start in NASCAR's second-tier series, was launched into the catch-fencing.
"I was getting pushed from behind, and by the time my spotter said, 'Lift," it was too late," said Larson, who was able to climb out of what remained of his vehicle.
"I had some flames come in the cockpit. I was all right and could get out of the car quickly. It was definitely a big hit."
Larson's car tore a hole in the fence separating the track from the stands. His engine sheared off with at least one tire and other debris flying into the grandstand.
"I looked in the mirror and that's the worst image I've ever seen in a race in my life," said Stewart, who was gearing up for Sunday's Daytona 500, the opening race in NASCAR's elite Sprint Cup series.
Stewart, a three-time Sprint cup champion, is an owner of the Stewart-Haas team for which Danica Patrick drives.
Patrick's sensational qualifying performance made her the first woman to claim pole position for a NASCAR race, drawing even more attention to this year's "Great American Race".
Organizers vowed the the speedway would be ready to host the 55th edition of the Daytona 500 on Sunday.
"We expect to go racing tomorrow with no changes," Chitwood said.
But the images of terrified fans dodging flying debris, with smoldering parts of Larson's car lodged in the fencing, will be slow to fade.
None of the drivers involved in the crash was injured, although driver Michael Annett was hospitalized with chest bruising after hitting a safety barrier in an earlier crash.
"We've always known since racing was started this is a dangerous sport," Stewart said. "We assume that risk. It's hard when the fans get caught up in it."
Chitwood said speedway and NASCAR officials responded appropriately, and emergency personnel responded promptly.
Steve O'Donnell, NASCAR's senior vice president for racing operations, said safety mechanisms such as tethers designed to prevent wheels and other car parts from flying into the stands worked properly.
"Some of the things we have in place, tethers, that sort of thing, held up, did their job," O'Donnell said.
"But certainly when you look at this incident, there are some things we can learn and evaluate. We'll take the car, we'll do that. We'll evaluate the fencing and see if there's anything we can learn from where gates are."