Prosecutors said Thursday there isn't enough evidence to bring criminal charges in the deadly thrill ride accident at this year's Ohio State Fair that killed a high school student and injured seven other people.

The State Highway Patrol, which led the investigation, said it interviewed over 80 witnesses, including people on the ride when one of its carriages carrying four people broke apart on the midway.

Franklin County Prosecutor Ron O'Brien said his review of the patrol findings led him to decide against moving forward with a criminal case.

The Fire Ball ride broke apart as it was swinging with a full load of passengers on the fair's opening day July 26, killing 18-year-old Tyler Jarrell, of Columbus.

Video taken by a bystander of the swinging, spinning ride in action captured the moment it came apart and two people were ejected and plunged toward the ground. Other riders were still in their seats as they fell.

The ride's Dutch manufacturer, KMG, said excessive corrosion within a support beam wore away the steel wall's thickness over the years, causing the catastrophic failure of the Fire Ball ride.

But its explanation didn't answer why or when the ride began rusting away or how it went unnoticed.

The company shut down similar rides worldwide after the accident and has said it developed new inspection guidelines.

The ride's operator, Amusements of America, submitted paperwork to the Ohio State Fair showing it completed ultrasonic testing of the ride's 24 gondola arm pins last October. But it's not clear whether the tests examined the area where the carriage broke.

Those tests are done based on the manufacturer's recommendations of where to look for potential problems.

The state's own ride inspectors do visual checks of the fair rides to make sure they're assembled and operating properly.