Abstract: At approximately 9:00 a.m. on March 11, 2009, Employee #,1 a stationary engineer, was assisting the delivery driver of the chemical delivery truck with a delivery of several plastic drums containing either sodium hypochlorite or hydrochloric acid. According to the Employee #1, the delivery was typical of many made to the pool to replenish the sodium hypochlorite, the chemical used to disinfect the pool water. The delivery area was in the basement utility room area beneath the pool and offices. Soon after arrival, the delivery Employee connected a small electric pump and hose from a 55-gallon drum of hydrochloric acid on the truck to the hypochlorite tank in a 10-ft by 10-ft room approximately 20 ft away. Soon after pumping began, Employee #1 reported that a strong chlorine odor was present. Upon emerging from his workstation immediately adjacent to the tank room, Employee #1 saw a green gas flowing from the top of the tank onto the concrete floor in front of the tank where he was standing. Employee #1 also stated that the other Employee was in the process of turning off the pump and leaving the area quickly on foot for higher ground just above the delivery area. Employee #1 then noticed that his lungs were hurting and went up into the pool area to warn and evacuate occupants and ensure that windows and doors to the downstairs areas were closed. Employee #1 was exposed to chlorine gas during the inappropriate transfer of hydrochloric acid into a tank. Employee #1 was hospitalized and treated for his injuries.