Attention turned to amusement park safety after a tree branch that fell on the tracks derailed a roller coaster car at a Six Flags amusement park Monday evening, leaving it dangling precariously and its occupants stranded for hours.
Four people were injured on the Ninja ride at Six Flags Magic Mountain, the Los Angeles County Fire Department said. Two of the four were taken to a hospital as a precautionary measure.

According to the International Association of Amusement Parks and Attractions, there are 4.3 injuries per million attendees at U.S. fixed-site amusement parks, citing 2011 statistics.
In 2011, the chance of being "seriously injured" at fixed-site amusement parks in the U.S. was 1 in 24 million, the IAAPA reported.
Still, it's hard to ignore images of a roller coaster car filled with people, drooping from the track.
The front part of the roller coaster detached from the track and dangled at about a 45-degree angle, pointing to the ground.
The car was about 20 feet in the air, Los Angeles Fire Department supervisor Ed Pittmann told KTLA.
Rescue workers climbed atop the track and used a thick rope to tie the front of the car to the track above.
By late Monday night, all 22 passengers had been rescued.