After five hours, all passengers rescued from Six Flags roller coaster

Authorities say 24 people stranded on a roller coaster have been rescued from near the top of the ride at Six Flags America in Maryland.

Prince George's County Fire officials say it took about five hours Sunday to rescue 17 adults and seven children from The Joker's Jinx roller coaster.

Assistant Fire Chief Paul Gomez says the riders were sitting upright. A few had cramps, back pain and dehydration, but there were no major injuries.

A Six Flags America spokesman said in a statement that it is not yet clear what caused the ride to stop but that it has a computerized safety system that "performed as it is designed to."

Six Flags' website says the ride goes 60 miles per hour and upside down four times.

Last week, at Six Flags Great Adventure & Safari in Jackson, N.J., passengers on the Nitro roller coaster found themselves stuck part way up the first 233-foot high hill of the ride. Six Flags park officials say a power outage to the ride was to blame. No one was injured as a result of the stoppage.  Ride operators climbed up, helped the passengers out of their seats, and down the stairs, NBC News reported.

Last month, the front car of the Ninja coaster at Six Flags Magic Mountain in Valencia, Calif., became dislodged after colliding with a branch lying atop the tracks shortly. It took rescue crews three hours to evacuate the 22 riders, one at a time, from the coaster. No one was seriously injured.

But as The Christian Science Monitor reported, the safety record for amusement park rides is improving.

Accidents at southern California amusement parks are relatively rare, a 2013 Los Angeles Times investigation of theme parks found.

The Times staff combed through more than 2,000 accident reports filed at 57 area parks between 2007 and 2012. Nearly one-fifth of those reports related to motion sickness. About 350 injuries occurred each year during the six-year period covered in the investigation. That’s a relatively small number compared with the total combined attendance of 40 million visitors each year.

Nationally, the number of injuries per million attendees has been steadily dropping since 2001, according to a survey of fixed-site ride injuries across the United States between 2001 and 2011, conducted by the National Safety Council's Research & Statistical Services Group in Itasca, Ill. The survey found that in 2011, about 4.3 people per million park visitors received injuries, compared with an average of 8.2 per million visitors in 2001.