A 12-year-old girl collapsed at a Disney World water park Thursday and later died, authorities said.

The girl was in the wave pool at Typhoon Lagoon (search) at about 6 p.m. when lifeguards noticed her lying on a ledge, out of the water, the Orange County Sheriff’s Office said.

Lifeguards asked her if she was OK, and the girl told them she was, but then passed out when she stood up. The lifeguards performed CPR until paramedics arrived. She was pronounced dead at a hospital a short time later.

“This is someone we approached and talked to, and after we engaged in conversation with her, she became ill,” said Disney spokesman Bill Warren.

The girl was with relatives from Newport News, Va. They said she had no known medical problems, the sheriff’s office said.

Her name was being withheld until her parents in Virginia were notified. An autopsy was planned.

In June, another child died at the theme park after riding Epcot’s “Mission: Space,” which simulates a shuttle ride to Mars. The cause of the 4-year-old boy’s death remains under investigation.

Disney World attracts millions of visitors annually.