Abstract: At 10:15 a.m. on July 30, 1986, Employee #1 was taking water samples to the Boonville water treatment plant. He was told by the plant operator that the indicator lights on the control panel indicated that a well field in eastern Spencer County was shutting on and off. Employee #1 told the plant operator that he would go to the water well field to check the problem. He then fueled his truck and traveled to the site, arriving at approximately 10:35 a.m. He was alone at the site. He left his truck, opened the door of the control room toward him, and smelled chlorine gas. Employee #1 then opened the door of the chlorine gas room. He ran back to his truck, moved it as far as he could, and called the Boonville Fire Department for help at approximately 10:47 a.m. Employee #1 later stated that nothing seemed very clear until he was in the Warrick County Hospital emergency room in Boonville. The building consists of two rooms. The control room is concrete block construction, 88 in. by 96 in. by 104 ft high with an outside steel door and ventilation. The chlorine room is concrete block construction, 120 in. by 96 in. by 104 in. high with an outside steel door, a disconnected chlorinator and electrical system with an outside light/exhaust for a switch, and a corroded, rested pump motor with rust on all inside walls.