An outbreak of Legionnaires’ disease in New York City has killed two people and sickened 58 since late July. City health officials link the Central Harlem outbreak to cooling towers, structures containing water and a fan that are used to cool buildings.

Two people have died and 58 others have fallen ill from a Legionnaires’ disease outbreak in Central Harlem in New York City, according to the New York City Health Department. Health officials announced the cluster on Monday, noting that cases have been identified since July 25 across five ZIP codes in upper Manhattan.

Fifty-eight people have been infected—and two have died—in a New York City outbreak of Legionnaires’ disease—a severe type of pneumonia caused by a bacterium commonly associated with air-conditioning