At least 28 fans and one driver were injured after a crash involving several cars at the Daytona speedway, when car debris flew into the crowd near the end of the Nationwide NASCAR race.
Race officials said 14 fans were sent to hospital, with another 14 being treated onsite.
Michael Annett, driver for the Richard Petty Motorsports team, was treated at the Halifax Health Medical Center in Daytona Beach and would be kept for observation, the team said in a statement.
Joie Chitwood, president of the Daytona International Speedway, has said that Sunday's main race will go ahead despite the recent incident.
"First and foremost, our thoughts and prayers are with our race fans," Chitwood 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. We are in the process of repairing the facility, and we will be ready to go racing tomorrow," added Chitwood.
Debris from the 10-car crash flew into the spectator area and amid chaotic scenes, some fans were taken away on stretchers.
The crash sent driver Kyle Larson's car airborne, although he climbed out of the wreckage afterward unhurt.
NASCAR's vice president of race operations, Steve O'Donnell, said that the fencing, which was ripped through by the flying debris, was being replaced and the incident would be reviewed
"We're very confident that we'll be ready for tomorrow's event with the 55th running of the Daytona, but as with any of these incidents, we'll conduct a thorough review, we'll work closely with the tracks as we do for all our events, learn what we can and see what we can apply in the future," he said.