SAN JOSE, Calif. (AP) — Authorities say 35 people have been taken to hospitals after they were exposed to a toxic gas cloud at a San Jose swimming pool.

The Fire Department says chlorine and muriatic acid were improperly mixed and formed a cloud of chlorine gas Thursday at the Shadow Brook Swim Club.

Authorities say swimmers as young as 6 were treated after some reported shortness of breath, stinging eyes, nausea or vomiting.

Fire Capt. Mitch Matlow tells the San Jose Mercury News that all those exposed were washed off, given new clothes and taken to hospitals.

A member of the board of directors of the Shadow Brook homeowners association told the paper that officials had no comment.