Your fear of roller coasters has just been validated. Two dozen visitors to Six Flags Magic Mountain amusement park in Los Angeles were trapped for almost three hours after the Ninja roller coaster train derailed. Guests were left dangling in a “precarious position,” said Michael Pittman of the Los Angeles County Fire Department, after a fallen branch on the tracks managed to send the coaster off the rails. Four riders sustained minor injuries. This is not the first theme-park horror story of the summer. Just last month, dozens were trapped on a SeaWorld San Diego ride.