California safety inspectors continued their investigation Wednesday into the partial derailment of the Ninja roller coaster at Six Flags Magic Mountain.
Park officials and witnesses described seeing a large branch fall across the tracks at about 6 p.m. Monday, causing the partial derailment, but a spokesman for the California Division of Occupational Safety and Health, Peter Melton, said an entire tree -- estimated at 40 feet high -- had actually fallen.
Magic Mountain has shut down the ride and is investigating the incident, along with Cal/OHSA.
"They're trying to find the problem and get the ride back up," Melton said.
Jeremy Ead was on the famous thrill ride about 6 p.m. when the derailment occurred, he told KCBS-TV Channel 2.
"We were going across one turn, and all of a sudden a loud noise happened," Ead told the station. "I ducked down just in time. A hard branch hit me in the head. I was there bleeding from my head."
The 22 people on the ride were safely evacuated about 8:30 p.m. after being stuck for nearly three hours. Two of the riders were taken to a local hospital as a precaution, said Magic Mountain spokeswoman Sue Carpenter.
Magic Mountain visitor Brandy Chambers was on a nearby ride when she saw the accident, she told KTLA-TV Channel 5.
"We were riding on the Jet Stream when we saw the Ninja go into the trees," Chambers said. "It was a lot of leaf noise and then cracking noises … and a lot of screaming."
A specialized urban search-and-rescue team was called in to assist with evacuating the riders, who were suspended about 40 feet above the ground. Stranded passengers could be seen talking to firefighters who were working to free them.
The Ninja will remain closed while inspectors survey the track and the area, Carpenter said.
"The safety of our guests and employees is our No. 1 priority," she said.