A case of acute chlorine gas exposure in a swimming pool attendant was previously reported (Clin Tox 13:377-381, 1978). In April 1986, approximately 30 people, including a swimming coach, lifeguards, and competitive swimmers ranging in age from 5 to 12 years old, were exposed to heavy concentrations of chlorine gas at a large indoor swimming pool. The coach, one lifeguard, and 18 of the children were hospitalized. In June 1988, a similar exposure occurred at the same swimming pool, and 11 persons were affected. Information from these 2 incidents illustrates 4 important factors in disaster prevention and management: proper training of equipment operators, effectiveness of triage, information flow to relatives of the afflicted, and requisite posthospitalization followup to detect possible long-term adverse effects.