Some of them were trapped upside down on a roller coaster during the holiday weekend, officials in Wisconsin are investigating.
The nightmarish incident took place at the Forest County festival in Crandon, a city of about 1,700 north-west of Green Bay.
Rescue workers responded to a report that passengers were stuck on a fairground ride and arrived to find eight people hanging upside down from their safety harnesses, according to a press release issued by the Crandon Fire Department. The fire department said roller coaster cars were stuck near the top of the loop with passengers being held in an inverted position by safety harnesses and that firefighters used ladder trucks to reach passengers and securing each one before releasing their over-the-shoulder safety bars. The rescue was also supported by a fortunate bystander who turned out to be an off-duty firefighter with specialized rope rescue training. One person was taken to a hospital, police said.
The exact cause of the incident is being investigated, but a rider described it as a mechanical failure, according to the fire department.
Wisconsin's state Department of Safety and Professional Services monitors plans for amusement parks and inspects rides. In an email to the Associated Press, beard said the agency is investigating and dispatched an inspector to the scene in Crandon. He didn't have any further information on possible findings.