There has been a fourth death from a Legionnaires' disease outbreak in New York City. The NYC Department of Health said there are 99 confirmed cases, with 17 people currently hospitalized, as of Thursday.

The health department offered five ZIP codes in central Harlem -- 10027, 10030, 10035, 10037, 10039 – that were at the center of the cluster, as officials stressed the disease was airborne and could reach people even outside of the directly affected buildings.