A preliminary investigation indicates that passengers may have been injured when the "Vortex" ride started up again as they were getting off, about 9:17 p.m. Thursday, fair spokesman Brian Long said.
He said an ambulance was on the scene immediately, and that two of the injuries "appear to be serious; the other three not as serious."
The injured riders ranged in age from 14 to 39, Wake County Sheriff Donnie Harrison told a news conference. Linda Fowler, clinical administrator for WakeMed in Raleigh, confirmed that five people were admitted to the hospital from the fair, but she did not give out further information.
The "Vortex" spins, twirls and flips passengers upside down. Long said the ride would undergo inspection by the state Department of Labor, and that the sheriff's office would also conduct its own investigation and look for witnesses.
Television station WRAL in Raleigh quoted witnesses as saying several people were thrown off the ride and that some were unconscious.
A witness identified as Caleb Norris told WNCN television that he heard a crashing sound just after getting off the Vortex. He turned around and saw two people lying face down. Norris also said he saw the ride operator fall to his knees and start crying.
The accident occurred shortly before the fair was shutting down for the night. Long said the fair would reopen on Friday as scheduled. It closes Sunday.
In 2002, a ride operator at the fair was killed when he was struck by the ride while it was still in operation.