California ? A 4-year-old boy drowned Thursday in a wave pool at the Paramount Great America amusement park, authorities said.

The boy was unconscious when park lifeguards pulled him from a two-foot-deep section of the Great Barrier Reef, according to Bill Lentz, Great America’s general manager. The 355,000-gallon attraction, which opened Memorial Day, simulates the sensation of ocean waves.

The lifeguards and Great America emergency workers administered CPR on the child until Santa Clara County paramedics arrived, he said.

The boy was taken by ambulance to Kaiser Permanente Medical Center in Santa Clara, where he was pronounced dead after additional attempts to resuscitate him failed, said Dave Parker, a spokesman for the Santa Clara County Fire Department.