The Legionnaires' disease outbreak in Central Harlem has been traced to 12 cooling towers, including several at city-owned and operated buildings like Harlem Hospital, officials said Thursday.

A cooling tower at Harlem Hospital was among 12 sites tied to the city’s Legionnaires’ disease outbreak that’s now killed four people and sickened nearly 100, Department of Health officials

A fourth person has died amid the Legionnaires’ disease outbreak in central Harlem, according to the New York City Department of Health. The outbreak that began in late July has since spread to 99 confirmed cases as of Thursday, with four deaths and 17 hospitalizations. Those who have died have not been identified.