Twenty-four people were stuck in a roller coaster that stopped 45 feet above ground at the Six Flags in Upper Marlboro, Maryland, on Sunday.

All two-dozen people were rescued by Prince George’s County Fire Department, seven of which were children. The firemen reportedly used a bucket to get everyone off the Joker’s Jinx safely. The passengers were unstrapped and removed from the cars one by one, according to WUSA 9. The rescue was completed in about four hours.

The malfunction occurred at around 2:30 p.m., and all of the passengers were back on two feet by 7 p.m..

Prince George’s County Fire Chief Marc Bashoor said that each rider was inspected by a medical professional before leaving the park, as reported by Reuters. No one was found to be hurt.

Six Flags released a statement explaining that despite its uncertainty of what caused the mishap, “the ride performed as it is designed to.” The ride will remain closed until investigators determine exactly what needs to be fixed.