A WNCN viewer told the station he saw operators working on the ride Thursday night that later injured five people.
And on Friday morning, state officials confirmed the ride, the Vortex, had a problem Monday.
Ken Vrana was at the State Fair Thursday and said he saw operators at the Vortex checking the ride, and said he felt operators were aware there was a problem.
"My wife and I were out at the Fair taking some photographs and just happened to be in front of that particular ride. I was waiting for them to start the ride so I could get some action stuff," Vrana said.
"It's a little bit of an unusual ride in the way they have to lock people in with one of these bars. And they kept messing with the bars and messing with them and they couldn't get the thing to lock down.
"And I got a little bit bored of waiting and was going to move on. And they still ultimately could not get them to lock down. And they started running that ride. And they ran it from 8:45 until the accident.
"So they knew there was a problem with that ride."
On Friday morning, state officials addressed the issue in a lengthy news conference at the Fair.
Tom Chambers, the chief of the ride inspection unit for the Department of Labor, confirmed that the Vortex ride had a problem on Monday with "a switch that was bad."
"They repaired it," he said. "We checked it and the ride went back into operation."
Chambers said that all rides are routinely inspected each day. As for the training of the operators, he said, "Typically, we don't look at the training as far as the operators are concerned. They are supposed to be trained to the manufacturer's specifications on the device."
He said his inspectors do "spot check."
"What we are looking for is, ‘Are the operators paying attention to the device, loading people properly,' these kinds of things," he said.
Officials insisted Friday morning that the rides at the North Carolina State Fair are safe, calling Thursday's stunning event "an isolated incident" as the Fair headed into its final weekend.
Five people were injured, two of them seriously, after an incident on the Vortex ride behind the Expo Center.
At a Friday morning news conference, State Agriculture Commissioner Steve Troxler said, "Safety is something we take very, very seriously."
He said he was proud of the fact that all five victims were cared for and off the site in 20 minutes.
"We're proud of the fact that our critical response plan worked just as we had planned," Troxler said.
He called what happened "an isolated incident" and urged people to continue to come to the State Fair for the final weekend.
"I still feel confident that my grandchildren can ride these rides," Troxler said.
Cherie Berry, the state's Commissioner of Labor, echoed a similar theme, saying, "If my children were here, I would put them on it."
She added, "I hope it will not dampen the spirit of this Fair."
But Friday morning's news conference was full of sharp questions and few answers as reporters sought more information on Thursday night's stunning events.
Wake County Sheriff Donnie Harrison said the victims are between the ages of 14 and 39. Harrison confirmed some of the victims are family members. One of the injured was a ride operator, Harrison said.
Harrison again said the incident happened after the ride had ended.
"What I was told earlier was the ride had come to stop and they were fixing to unload and then something happened," Harrison said.
After the ride stopped, he said, it somehow started again.
Harrison said the families had asked that their names and specific conditions not be released and he would not go into details about how they were hurt. Harrison said his department is still interviewing multiple witnesses to find out what happened.
"That's part of our investigation," Harrison said. "That's what we are trying to make sure. We've heard a lot of rumors."
The company that manages the rides is Powers Great American Midway. Owner Les Powers told The Associated Press on Friday he didn't know what caused the accident.
"Nobody wants this to happen, and we're trying to find out why this did happen. Until I find out any information, I can't even give you a clue," Powers told The AP. He said the Vortex is owned by a Georgia-based carnival owner.
In a state on their Facebook page, Powers Great American Midway said, "Powers Great American Midways is deeply sadden by the tragedy at the North Carolina State Fair on Thursday night. We are working progressively with the North Carolina Department of Labor ride inspectors and the Wake County Sheriff's Department to discover the cause of this problem. The ride is owned and operated by an independent company."
Brian Long, public affairs director with the State Fair, said the ride is located between gates 4 and 5 on the lower midway.
Long said an ambulance was on scene within a minute of the first call just after 9 p.m. Long said all five victims were transported to WakeMed by 9:37 p.m.
Richard Gephart heard the accident while on the Midway.
"It just sounded like a bunch of stuff hitting metal. And that was it. There was no screaming," he said.
And Caleb Norris also said he saw the ride operator fall to his knees and start crying.