Abstract: Employee #1 and #2 were janitors for Kass Management Services, was performing janitorial tasks at the Social Security Building in Richmond, CA. The water used for mopping and other cleaning duties was connected to the tepid water system, which was contaminated with Legionella Pneumophila Serotype One; the water sample taken from the sink used for washing and mopping tested positive for Legionella. Employee #1 died and the autopsy report indicated that her death was caused by respiratory failure due to massive bilateral bronchopneumonia. The causative organism was identified as Legionella Pneumophila Serotype One. Employee #2 also died.