(CNN) -- A chlorine leak at the Raging Waters water park in Sacramento, California, sent nine children and 11 adults to local hospitals Monday, officials said.
"There was a pretty strong smell of chlorine in the air when we got here," Assistant Fire Chief Niko King said. Several people complained about burning eyes, he said.
According to the Centers for Disease Control and Prevention, chlorine exposure can cause a burning sensation in the nose, throat, and eyes, as well as nausea and vomiting.
Early indications are that there was a problem with the mechanical system that delivers chlorine to the pools at the complex, according to King, who said the leak appeared to be confined to a children's wave pool.
County environmental officers are conducting an investigation.
CNN's Greg Morrison contributed to this report