1976 Philadelphia Legionnaires' disease outbreak killed 16 persons out of 78 infected was later determined to be Legionnaires' disease. A September 1974 convention of the Independent Order of Odd Fellows was also held at the Bellevue-Stratford Hotel. Out of approximately 1,500 members who attended, 20 developed pneumonia and two died. A later article in "The Lancet" reported: "Illness [high fever and pneumonia] was significantly associated with attendance at one convention activity held on Monday morning, September 16, 1974, in the grand ballroom of the hotel." 1976 Philadelphia Legionnaires' disease outbreak The 1976 Legionnaires disease outbreak, occurring in the late summer in Philadelphia, Pennsylvania, was the
1976 Philadelphia Legionnaires' disease outbreak 25 had died. Both the first week and later, there were 149 Legionnaires who became sick and 33 other persons associated with the hotel or in the area who also became sick. Of these total of 182 cases, 29 persons died. The U.S. Centers for Disease Control and Prevention mounted an unprecedented investigation and, by September, the focus had shifted from outside causes, such as a disease carrier, to the hotel environment itself. In January 1977, the "Legionella" bacterium was finally identified and isolated and was found to be breeding in the cooling tower of the hotel’s air conditioning system,