OCEAN CITY, N.J. (AP) _ Four people were hurt Saturday night after an accident on a roller coaster at an amusement park on the beachfront Boardwalk.

Neither police nor officials at Wonderland Pier would release information about the 10 p.m. accident. But witnesses said one car crashed into the rear of another on the Wild Wonder ride.

Robert Lee, 11, who lives a few hundred feet from the pier, said he heard a crash and thought it was a car or truck coming to a sudden stop on the street. He said a police officer told him that one roller coaster car got stuck on the tracks.

``The car behind it came in and hit it from the rear and knocked the people in the first car out of the car,'' he said.

One adult and one child were in critical condition and an adult and child were in serious condition, said Heidi King, nursing supervisor at Shore Memorial Medical Center. Of those victims, one child was taken from scene in in a neck brace and two other patrons were taken away bleeding, witnesses said.

E.J. Miranda, a spokesman for the state Department of Community Affairs, said inspectors would be at Wonderland Pier on Sunday to check the roller coaster.

``The ride will remain shut down while that investigation takes place and won't reopen until we're satisfied that we know what happened, why it happened and that it won't happen again,'' Miranda said.

Kathleen McAlary, a spokeswoman for Wonderland Pier, refused to comment and requested that a reporter leave.

The Wild Wonder is a two-story roller coaster with cars designed to look like animals.