ANTIOCH (CBS SF) — About 40 people, mostly children, fell ill Thursday afternoon due to a possible chemical exposure at an East Bay water park.

At 2:29 p.m., emergency crews responded to reports of a child complaining of respiratory problems after swimming at Antioch Water Park, located at 4701 Lone Tree Way, according to a fire inspector with Contra Costa Fire Protection.

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“We just heard people screaming, saying their throat burned,” Marquan George told KPIX 5.

The chemical exposure may be due to excessive chlorine that leaked into the pool, Fire Inspector Lisa Martinez said.

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As of 4 p.m., 10 to 15 people had been taken to the hospital, Martinez said.

Parents arrived at the park to pick up their children.

Hazmat crews also arrived on scene to determine the cause of the exposure, according to Martinez.

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