Updated 11:44 a.m. ET
RALEIGH, N.C. Officials said Friday the North Carolina State Fair midway ride where five people were injured late Thursday needed repairs three days earlier when a switch failed, reports CBS Raleigh affiliate WRAL-TV.
According to WRAL-TV, the first emergency call came in at 9:17 p.m. Thursday, about an incident involving a ride called the Vortex.
The Vortex will remain shut down for the rest of the fair, spokesman Brian Long said, as investigators try to determine what led to the mishap.
The injured ranged in age from 14 to 39, and some came from the same family, said Wake County Sheriff Donnie Harrison. One of the injured was a ride operator.
"The ride had stopped and they were fixing to offload when it started up again," Harrison said, adding that it wasn't clear whether there was a mechanical malfunction or whether human error was involved.
Crime scene investigators were at the scene, and North Carolina Labor Department spokesperson Dolores Quesenberry said when they were done, ride inspectors would begin their work looking at every piece of The Vortex, which is operated by Powers Great American Midways - to try to find out what went wrong.
Investigators were interviewing around 35 to 40 people who might have witnessed what happened. "It's going to take quite a while talk to all these people," Harrison said.
The sheriff asked anyone who might have been recording video in the area where the incident occurred to contact authorities.
All five victims were taken to WakeMed Health & Hospitals in Raleigh. Harrison said two of the injured were in critical condition and "the other three were in not that bad a shape," although he could not provide further details. Two were later released.
Officials could not say how long the ride and adjacent attractions might be closed, but said the fair would be open Friday.
"This has shaken all of us a little bit and we definitely have these folks in our thoughts and prayers tonight," Brian Long, a spokesman for the North Carolina State, told a news conference.
Quesenberry said rides are normally inspected three times a day.
Harrison said fair-goers should rest assured that rides are safe.
"I know the ride inspectors will do their due diligence," he said. "As sad as it is, we want people to come out and have fun.
According to a description of the ride, the main arm is hydraulically lifted to a 30-degree angle and the V-shaped center of the ride starts rotating while the car arms also rotate, each in a different direction.
Witnesses told WRAL everything appeared normal and then, all of a sudden, they saw a rush of emergency personnel and fairgoers frantically converging to the area.
A number of people were lying on the ride's platform, and some weren't moving and some appeared to be under a portion of the ride.