Timeline Wednesday 21 July 1976

Events on Wednesday 21 July 1976 1

• 1976 Legionnaires' disease outbreak Mystery pneumonia outbreak strikes Philadelphia convention In late July 1976 an outbreak of severe pneumonia among attendees of an American Legion convention in Philadelphia killed 34 people and sickened over 180. The cause was traced months later to a previously unknown bacterium, subsequently named Legionella, spreading through the hotel's air conditioning system. The event gave the disease its common name, Legionnaires' disease.