"My fault," conceded JR Motorports driver Regan Smith as the dust settled on one of the most violent accidents seen at Daytona International Speedway in recent years.

Smith had been leading Tony Stewart on the final run to the finish of the Drive4COPD 300 Nationwide Series race when Brad Keselowski tried a move around the outside, and Smith had reacted to head him off.

"I threw a block, I'll take the blame for it," Smith said. "I knew coming off 4 I was going to have to throw a block ... When you see the chequered flag at Daytona, you're going to block, and you're going to do everything you can to be the first car back to the stripe.

"You gotta do what you gotta do. You gotta go for it. Brad's a good friend. He pushed me to the front, and we're both wanting the race," Smith told ESPN after the race. "That's a product of the tandem racing. Brad knew he was going to make a move. And that was all there was to it.

"If I had to [do it again], yeah absolutely. You're coming to the chequered at Daytona, it doesn't matter if it's a Nationwide race or a kart race, you want to win here," he admitted. "I couldn't play it any different other than to just concede second place, and I wasn't going to do that today. Our guys work really hard on these race cars all year long, and our job is to put them in a position to win. It was, and it didn't work out.

"Certainly want to do the same thing tomorrow. If I'm in the same position tomorrow, I'll do the exact same thing," he insisted. "It just didn't work out today. Just hoping everything is okay, everyone who was in the wreck and all the fans."

The accident ended up launching Kyle Larson's car into the air where it impacted the catchfence. The engine block tore through the fencing and scattered debris into the spectator area nearest the track, and one tyre was thrown into the air and landed in seating some 20 rows up. Medics attended casualties in both areas as circuit officials cleared the grandstands.

Daytona International Speedway President Joie Chitwood issued an official statement on Saturday evening regarding the crash. "First and foremost, our thoughts and prayers are with our race fans," he said.

"Following the incident, we responded appropriately according to our safety protocols and had emergency medical personnel at the incident immediately. We transported 14 people off property and 14 were treated at our on-track care center," he continued. "We are in the process of repairing the facility, and we will be ready to go racing tomorrow [Sunday.]"

Seven injured fans went to Halifax Medical Center in Daytona Beach, and six to nearby Halifax Health in Port Orange. A spokesman from Halifax Health said that all but two of their patients had been discharged by Sunday afternoon. The status of the two remaining patients previously listed in critical condition after the accident had been upgraded overnight and they were now said to be stable. The other injured fan had been taken to Florida Hospital Memorial Center, but a spokesman there would not disclose the patient's condition.

In the circumstances there was understandably little appetite for celebration in victory lane, and drivers were also steadfastly avoiding playing the blame game.

Brad Keselowski for one wasn't about to criticise Smith for the move that caused the wreck. "We made a move to try and win the race. We were in the catbird seat, Regan was in a good spot. He was first and I was second and we were pushing.

"I kind of had the run and the move to win the race, and Regan obviously tried to block it, and that's understandable. He wants to win too, and at the end it just caused chaos.

"I really hope everyone in the grandstands is okay, I think that's the most important thing right now," Keselowski added. "There was obviously a big wreck with a lot of debris and cars torn up."

"It happens on the last lap," said Dale Earnhardt Jr., who was involved in the wreck himself and is also the car owner of Smith's #7 entry. "Always does. You can bet on it."

"We've always known since racing was started this is a dangerous sport," race winner Tony Stewart said in the winner's circle. "We assume that risk. It's hard when the fans get caught up in it."

Despite Larson's car being literally torn in half by its encounter with the catchfence, the 20-year-old Japanese-American series rookie was miraculously able to climb out and walk away from the wrecked #32. He was later examined and cleared by the medical centre, along with all the other drivers involved.

"It's definitely been one I'll never forget," the young Earnhardt-Ganassi driver said. "Yeah, it was definitely a big hit. Hopefully, I don't have another one like that in stock cars."

For former X-Games star Travis Pastrana - now a full-time Nationwide driver with Roush Fenway Racing - it was the first time that he had been right at the heart of a Daytona 'Big One.'

"I was right in the middle of it going backwards through the grass," he said. "I've got a lot of grass on me. I was told this wasn't a dirt race, but I always seem to find a way."

Pastrana, who went on to finish in tenth place, had also been involved in an 11-car wreck half an hour before which had caused a 20 minute red flag for clear-up operations.

"I saw the #43 take a hard, hard right about an inch in front of me at about 190 and, I tell you what, if that doesn't get your heart going, nothing will," he explained. "It was wild."

Only one driver ended up being hospitalised on Saturday afternoon, and that was as a result of that previous multi-car crash half an hour before the end. Richard Petty Motorsport subsequently released a statement regarding the condition of the driver of their #43 car.

"Michael Annett is currently being treated at the Halifax Health Medical Center in Daytona Beach, Fla. after an accident during Saturday's Nationwide Series event. He will be kept for observation," said the team.

"Annett was transported to the hospital after complaining of pain in his chest and sternum. Annett was treated for bruising on his chest and underwent a CT Scan," the team added. He was kept in hospital overnight and discharged on Sunday morning; he will need further assessment before being cleared to race at next week's event in Phoenix.

NASCAR's senior vice president for racing operations Steve O'Donnell said that an investigation would be held into the crash and lessons would be learned.

"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," he said. "I think we need to take the time to really study it and see what we can improve on. If we can, certainly the safety of our fans is first and foremost and we'll make that happen," O'Donnell promised.

"The biggest thing we know is we don't know everything we need to know because there are moments that occur that we've just never seen before and can't really plan for," added NASCAR president Mike Helton on Saturday evening. "That's evidenced everywhere we go with the fences, cables, structures, and the gaps between the racetrack and the seating area. We're always made aware of the fact that we don't know everything."

NASCAR and track officials confirmed that the Daytona 500 would proceed as scheduled on Sunday afternoon, and that all necessary repairs to the fencing and seating would be complete in time. "We don't anticipate moving any of our fans," said Chitwood.

The track president insisted that there would be no changes needed to the spectator area on the grounds of safety.

"We had our safety protocols in place," Chitwood said. "Our security maintained a buffer that separates the fans from the fencing area. With the fencing being prepared tonight to our safety protocols, we expect to go racing tomorrow with no changes."

Motorsports venues have been looking for a better alternative to catchfences for several years, and especially since Dan Wheldon's tragic death in a 2011 IndyCar race at Las Vegas Motor Speedway. However, there have been no proposals for systems that would deliver the same sort of safety advance as achieved by the development of the HANS driver neck support and the SAFER barriers which reduce the level of impact of a car against speedway retaining walls.

However, NASCAR did face criticism after the crash for using legal powers under the US Digital Millennium Copyright Act to order websites to immediately remove any fan-shot video of the incident from social media sharing sites including YouTube

Tickets to any NASCAR event bear explicit terms and conditions restricting the recording of the race and the sharing of any video or photos that a fan may have made while attending the event. Most US sporting franchises have similar terms - NFL provisions even technically forbid fans to write about what they see at a game.

NASCAR said that they had exercised their DCMA powers in this case in order to respect the privacy of the fans involved in the incident and to spare unnecessary anguish and suffering to families and friends who might see distressing footage of their loved ones being injured.

"The fan video of the wreck on the final lap of today's NASCAR Nationwide Series race was blocked on YouTube out of respect for those injured in today's accident," said a statement from NASCAR released on Saturday evening. "Information on the status of those fans was unclear and the decision was made to err on the side of caution with this very serious incident."

YouTube eventually reinstated access to the material, telling The Washington Post: "Our partners and users do not have the right to take down videos from YouTube unless they contain content which is copyright infringing, which is why we have reinstated the videos."