ANAHEIM, Calif. - The "California Screamin'" roller coaster at Disney's California Adventure theme park remained closed Saturday, a day after an accident that slightly injured 15 people.

Most of the victims were treated for minor neck and back injuries at a hospital and released late Friday night, Anaheim city spokesman John Nicoletti said. Another 33 people were examined at the scene but did not require treatment.

The crash occurred at about 6:40 p.m. Friday when one coaster rear-ended another. The ride was closed but the rest of the park remained open. The California Division of Occupational Safety and Health was contacted to help determine the cause of the crash.

The Disneyland Resort said in a statement that a moving train struck a stationary train and neither derailed.

"We are taking all necessary steps to help those affected by this incident," the statement said.

Though the coaster can reach speeds of 55 mph on steep drops, Nicoletti said the trains apparently hit at a low speed. The crash happened near the end of the ride on a horizontal stretch of the coaster track.

"It looked like a fender-bender," Nicoletti said.

Twenty-four people were inside each coaster. Eight had to be helped off by emergency personnel and the rest were able to use a catwalk to exit on their own.

Kevin Bromagen and his 6-year-old daughter, Taylor, said they had headaches and stiff necks after the coaster they were riding in was struck.

"You could hear the coaster coming before it hit you," said Bromagen, 38, of Lincoln, Neb. "The car came and smacked me in the back at full speed."

Disney's California Adventure, which opened in 2001, was designed to turn Disneyland into a resort destination, much like Disney theme parks in Florida, Paris and Tokyo. The adjacent Disneyland park is celebrating its 50th anniversary this year.

Friday's accident was the second in four months at a Disneyland Resort park. In March, a 4-year-old boy broke a finger and severed the tip of his thumb on the Storybook Land Canal Boats ride at Disneyland. The ride closed for nearly two days during an investigation. Four people were hurt in December when a float at a Disneyland parade struck them.

The most recent death in an accident at the park came in 2003, when a 22-year-old man was killed and 10 people were injured when cars on the Big Thunder Mountain Railroad ride derailed. State authorities concluded the accident was the result of mechanical failure caused by improper maintenance. (Mercury Nerws)