UPPER MARLBORO, Md. (WJLA/AP) - Rescuers pulled 24 stranded riders from the top of a 79-foot-tall roller coaster at Six Flags America in Upper Marlboro on Sunday after the ride halted on the tracks.
Video from NewsChopper 7 showed firefighters using ladder trucks to slowly help passengers to safety, one by one, from the train on the Joker's Jinx coaster.
Five hours after the rescue operation began, Prince George's County Fire Chief Marc Bashoor said all passengers - 17 adults and seven children - were safe.
The riders were sitting upright, he said. A few had cramps, back pain and dehydration, but there were no major injuries.
Bashoor said rescuers trained for months on rides just like this throughout the region, in case of just such an emergency, including the new wheel at National Harbor.
According to Six Flags, the ride has a computerized safety system that can cause the ride to stop if there is a problem detected.
"While we are not yet sure what caused the stoppage, the ride performed as it is designed to," said a statement issued by Six Flags spokeswoman Debbie Evans.
Six Flags' website indicates that the ride normally lasts for just over a minute, reaches a speed of 60 miles per hour in just seconds and goes upside down four times.
"Without any pauses or braking, you'll blast through a cobra roll, a sidewinder loop, a corkscrew, and countless swift reversals in between," the website description says, adding that the ride will "wipe that smirk off your face as you are shot like a bullet into four inversions compressed into a half-mile pile of twisted steel."
Evans said Sunday evening that the Joker's Jinx would be shut down while officials determine what happened.
"The ride will remain closed until the park completes a thorough investigation and both the staff and ride manufacturer have determined the ride is safe for operation," the Six Flags statement said.
It is unclear at this time how long that investigation will last.