The Legionnaires' disease outbreak in Harlem has been traced to 12 cooling towers, including several at city-run buildings, officials said.

Four people have died as a result of a Legionnaires’ disease outbreak in Harlem that has sickened nearly 100 people, and officials revealed the cooling towers that tested positive for the bacteria that causes the illness — some of which are at properties owned by New York City,

Legionnaires’ disease is a rare condition, and incidence is hard to estimate because diagnosis requires a suspicion of disease and ordering of the tests needed for confirmation, said Krishna Thavarajah, MD, a pulmonologist and director of the Interstitial Lung Disease Program at Henry Ford Hospital, Detroit, in an interview.

The deadly Legionnaires’ outbreak gripping Harlem has city officials in hot water — as locals accused them Friday of dropping the ball on life-saving inspections and needlessly slow-walking revealing exactly where the disease hit.