A low-hanging metal plate quickly became the focus of federal inspectors' attention last summer as they worked to determine what caused three girls to fall from the gondola of a Ferris wheel at the Greene County Fair, records obtained by WBIR 10News show.

After the girls plummeted one-by-one some 40 feet to the ground Aug. 8, the opening day of the fair in Greeneville, authorities noticed there was a quarter-inch gap between a "skid" plate on the girls' gondola and a metal bar below it, according a report from the federal Consumer Product Safety Commission.

This phone from the CPSC report shows the damaged skid plad on the affected gondola.

While the report sheds light on many details, the authors are careful to note it does not make a final determination as to the cause of the incident.

The Ferris wheel at the Greene County Fair remained closed Tuesday as inspectors reviewed an apparently mechanical failure on the ride that led to three girls falling from a gondola.

When they put sandbags in the gondola to replicate the girls' weight, the plate, located on the bottom of the gondola, made contact with the metal bar, the report from commission inspectors shows.

The 6- and 10-year-old girls have been identified as Briley and Kayla Reynolds. They were with a 16-year-old friend in the car when they fell, requiring hospitalization in Johnson City. Briley suffered a brain injury.

The federal report, obtained through a records request, also reveals that a fourth person was injured in the incident.

More: 6-year-old released from hospital

More: Parents of victims speak about incident

The unnamed 47-year-old woman was riding in an adjacent gondola with her granddaughter. She suffered a sprained left arm/shoulder, the report states. The child was uninjured.

The girls' gondola struck the car next to it as it pitched forward, authorities have said.

A witness told investigators he saw the girls fall one by one after losing their grip on the damaged basket, the report states.

Authorities last summer cited "mechanical failure" as the reason for the incident.

Kayla Reynolds, left, and Briley Reynolds, right 

The ride is operated by Family Attractions Amusement LLC of Valdosta, Ga.

"The owner stated that the (gondola) baskets were heavy and required a forklift to move them long distances," the federal report summary states. "He said it was typical for the baskets to be slid on the ground during assembly and disassembly."

According to the report, the skid plates on the Ferris wheel had never been replaced. They weren't marked for inspection either, according to the ride's owner, Dominic Macaroni.

Reached for comment Tuesday, Macaroni said he was not aware that investigators found bolts to be missing from the ride. He would not comment on whether his crew performed a thorough enough inspection prior to operating the wheel.

In 2013, a ride linked to Family Attractions LLC malfunctioned and injured a family at the North Carolina State Fair, according to a report by the North Carolina Department of Labor. Dominic Macaroni's son, Joshua, was charged in the incident and accused of tampering with safety mechanisms.

The Greene County Ferris wheel was a "prototype" from the manufacturer, High-Lite Rides of Greer, SC. High-Lite did not immediately return requests for comment.

Federal investigators from the U.S. Product Safety Commission inspect a Ferris wheel at the Greene County Fair on Aug. 10, 2016.

"(Federal investigators) noticed that all of the baskets had contact wear on their bottom skid plates," the report summary states. "Damaged or missing rivets were also noted. In several instances, pieces of gravel were visible in the gaps between the skid plate and the bottom of the baskets."

The owner told investigators the ride had been cleared for use after inspections this year while in Florida, Georgia, Indiana, Illinois and Kentucky.

It is currently in use at fairs across the U.S., and was repaired by the manufacturer, according to Macaroni. He said they have replaced the previous aluminum rivets with steel ones. He claims inspecting the skid plates was not mandated by the ride's owners manual, but is now done during setup.

10News recently spotted it at a fair in South Carolina.

10News asked if Macaroni believes the new rivets will prevent a repeat incident.

"I hope so," he said. "I don't want anybody to get hurt on any of my rides."