Send us Fan Mail The Duo recaps and reviews Season 1 Episode 7 titled "Legionnaires Disease". In the summer of 1976, during America's Bicentennial celebrations, 180 Legionnaires contracted an aggressive pneumonia-like illness after a convention in Philadelphia, Pennsylvania. After 29 of them die, doctors and scientists are puzzled. The determination of one scientist helps to discover the cause of this deadly disease now known as Legionnaires' disease. This became one of the most famous ...