A Legionnaires' disease cluster in the Harlem area of New York City has caused six deaths and sickened over 110 people. Here's what it is, symptoms and how it's spread.

Another person sickened in the Legionnaires' disease outbreak in Harlem has died. This is the sixth death reported in connection to the outbreak, which was first reported July 25. As of Thursday, there have been 111 confirmed cases and seven people are currently hospitalized.