Two roller coaster cars collided Thursday night on the Pony Express ride at Knott's Berry Farm, sending 10 riders to the hospital.
According to KTLA-TV, a ride car leaving the boarding station "rolled back," slamming a second car car inside the station that was boarding other guests.
The crash happened during Knott's "Halloween Haunt" event about 8:15 p.m. on Thursday. Authorities said the injuries were minor.
The Pony Express was built at Knott's Berry Farm in 2008. It launches from zero to 38 miles per hour in 3 seconds and reaches a top speed of 40 miles per hour, relatively tame by today's roller coaster standards.
Rollbacks, while not common, are a regular occurrence on roller coasters. They happen when a ride car is not launched fast enough to make it to the top of the first lift. This can be caused by a number of factors, including wind gusts, cold weather and ride cars that don't have enough passengers and therefore they don't have enough momentum.
Most coasters have a chain lift or other device to prevent rollbacks, as well as a braking system to stop a car if it does roll back.
There's no word yet as to the cause of the Pony Express roller coaster rollback.
http://www.gadling.com/2010/10/08/roller-coaster-crash-injures-10-people-at-knotts-berry-farm/
Video link:
http://www.ktla.com/videobeta/?watchId=11fa5fc3-0fcd-4ece-b038-da59900937a5
The first POV footage is from the CoasterForce YouTube channel.