State officials said the "Fire Ball" ride had been inspected earlier in the day before it "malfunctioned" at 7:24 p.m. A video posted online showed part of the ride breaking off mid-swing and throwing riders through the air.
News 5 is choosing not to show the video due to its graphic nature but you can see screen grabs from the video below.
Dr. David Evans of OSU Medical Center, which received three patients from the incident, said "multiple passengers were ejected at high speed" from the ride, traveled at least 20-30 feet and then "crashed at a significant distance from the ride."
An 18-year-old was killed, officials said. Three were still listed in critical condition late Wednesday night. Others were in stable condition. Evans said the three patients at OSU Medical Center would likely remain hospitalized for a week.
Gov. John Kasich joined state ride inspectors to give an update on the incident Wednesday night.
"The fair is about the best things in life, and then tonight with this accident, it becomes a terrible, terrible tragedy," he said.
Kasich ordered all rides at the fair be shut down pending inspections.
The Ohio State Highway Patrol was investigating the incident. Ride inspectors with the Ohio Department of Agriculture were also working to inspect all the rides again, department Director David Daniels said.
All "amusement rides" in Ohio must be inspected and licensed by the state Department of Agriculture by law. The state issues annual permits to ride owners after successful inspections.