A third person has died in a growing outbreak of Legionnaires’ disease centered on Manhattan’s Upper East Side, city health officials confirmed, as authorities ordered dozens of buildings to clean and disinfect their cooling systems to contain the spread of the bacterial infection.
The New York City Department of Health and Mental Hygiene announced the latest fatality on Sunday, bringing the death toll to three since the cluster was first identified earlier this month. The outbreak has sickened at least 19 people, with several patients still hospitalized. Health officials have not released the identities of the deceased, but local media reported that the second victim was an Air Force veteran and businessman who lived in the affected neighborhood.
In response to the cluster, the health department issued emergency orders requiring 76 buildings in the Upper East Side to inspect, clean, and disinfect their cooling towers — the primary source of Legionella bacteria, which thrives in warm water systems. The orders cover structures ranging from residential apartment towers to commercial properties. Building owners have been given a deadline to complete the work or face fines.
Legionnaires’ disease is a severe form of pneumonia caused by inhaling aerosolized water contaminated with Legionella bacteria. It is not transmitted from person to person. Symptoms include cough, shortness of breath, fever, muscle aches, and headaches. Older adults, smokers, and people with weakened immune systems or chronic lung conditions are at highest risk.
The outbreak has raised alarm among residents of the Upper East Side, a densely populated neighborhood with many older buildings. The health department has set up a testing and information site in the area and is urging anyone with symptoms to seek medical attention promptly. Officials are also conducting environmental sampling to identify additional sources of contamination.
This is not the first time New York City has faced a Legionnaires’ outbreak. In 2015, a major cluster in the South Bronx killed 12 people and sickened more than 120, leading to a citywide law requiring registration and regular inspection of cooling towers. Despite those regulations, outbreaks continue to occur, often traced to poorly maintained or infrequently disinfected systems.
The current cluster is concentrated in a roughly 20-block area of the Upper East Side, between East 60th and East 80th streets. Health officials believe the source is one or more cooling towers in the vicinity, though they have not yet pinpointed the exact origin. The investigation is ongoing.
City Council members representing the district have called for stricter enforcement of existing cooling tower rules and for more frequent inspections. Some have also proposed expanding the city’s monitoring program to include additional types of water systems, such as decorative fountains and misters, which can also harbor Legionella.
For now, the health department advises building owners to ensure their cooling towers are properly maintained and treated with biocides. Residents are encouraged to run taps for a few minutes before using water, especially if the building’s water system has been idle, and to avoid using hot tubs or spas that may not be well maintained.
The outbreak has drawn attention to the ongoing challenge of preventing waterborne diseases in urban environments. While New York’s water supply itself is safe, the complex network of pipes, tanks, and cooling systems in large buildings can create conditions where bacteria flourish. Public health experts say that regular maintenance and rapid response to clusters are essential to minimizing harm.
As the investigation continues, health officials are monitoring for additional cases and have urged doctors in the area to be vigilant for symptoms of Legionnaires’ disease, especially in patients with underlying health conditions. The health department has also set up a hotline for residents with questions or concerns.