Ten Alabama children were treated for exposure when incompatible chemicals were mixed at a condominium pool.

The incident occurred at the Phoenix on the Bay condominium pool in Orange Beach on June 20.

The Orange Beach Fire & Rescue were met by parents and children who were having difficulty breathing. Crews determined that someone had mistakenly added chlorine tabs to muriatic acid, which resulted in a caustic vapor, responders said.

Firefighters evaluated the parents and children who were experiencing minor symptoms.

All patients refused transportation by ambulance, and none who were affected by the chemicals were taken to the hospital.

Billy Widely, who works with the condominium’s management company, said that an employee regularly adds chemicals to the pool, but no one is sure how the mix-up happened.