Updated

The parents of two girls who fell more than 30 feet from a Ferris wheel at an eastern Tennessee county fair say they tried to alert the operator that something was wrong, but the ride was moved ahead despite their shouts.

During a hospital news conference in Johnson City on Tuesday, parents Jason and Kimmee Reynolds described their anguish at seeing their daughters and a third girl topple out of their carriage and fall to the ground.

"When he was pushing go, we took off running and were yelling `Stop, stop, stop!"' Kimmee Reynolds said. "And he just looked at us and he pushed the button anyway, and so we watched them tumble out, just one by one."

Inspectors have blamed the overturned carriage on worn-out rivet fasteners that allowed the facing to become loose and get lodged in the frame of the wheel.

Ten-year-old Kayla broke her arm in the fall at the Greene County Fair. Her 6-year-old sister Briley was knocked unconscious, and her parents feared she had died. Briley was taken to the hospital in critical condition, but was upgraded to stable condition on Tuesday.

An unidentified 16-year-old girl was also injured in the fall.

Jason Reynolds said he could tell before the fall that his daughters knew something was amiss.

"We could see their faces from the ground, and you could tell they were terrified, they knew something bad was going to happen," he said. "You could just see (Kayla) trying to grab for something to hold on to. It was horrible."

Kimmee Reynolds became tearful while recounting her emotions.

"They were trying their best to hold on, and then Kayla couldn't hold on anymore and started to drop. The whole crowd just gasped," she said. "That whole reaction, I can just hear that in my head, over and over."

The parents are calling for better safety standards and inspections for carnival rides.

"When you've got companies here that provide a service to the public, safety should be the priority," Jason Reynolds said.

Tennessee relies on out-of-state safety certifications and third-party inspectors hired by operators before issuing permits for rides.

It's not the first time people have been hurt on rides operated by the Ferris wheel's owner, Family Attractions Amusement of Valdosta, Georgia.

Five people were injured at the North Carolina State Fair in 2013 when a ride called the Vortex unexpectedly restarted as they were trying to get off the ride. Investigators determined that a safety mechanism had been disabled by ride operators, including the son of the company's owners.

Dominic and Ruby Macaroni's son Joshua was jailed earlier this year and North Carolina regulators fined him and Family Attractions Amusement more than $56,000 each.

Kimmee Reynolds said she wouldn't have let her children get on the rides in Greene County if she had been aware of that history.

"Knowing that the company had had problems before, that there had been other lawsuits and people injured and this kind of thing," she said. "Why did we continue to use them?

"I wish I had known, because we wouldn't have been there," she said.