South Bronx Legionnaires’ Cluster Leaves One Dead as City Tests Cooling Towers

New York City is investigating a likely community cluster of Legionnaires’ disease in parts of Melrose and Morrisania in the South Bronx after five people were diagnosed and one person died, according to the Health Department’s September 10, 2026 announcement.

The affected area includes ZIP codes 10451 and 10456. Confirmatory results for other potential cases were still pending as of that announcement, so the case count may change as the investigation continues.

Cooling-tower samples are being tested

The Health Department has completed sampling active cooling towers in the affected area. Laboratory testing for Legionella bacteria is ongoing.

Officials have not identified a specific cooling tower as the source of the illnesses. If a tower tests positive, the building owner will be directed to complete remediation, including draining, cleaning and disinfecting the system.

Cooling towers are part of large air-conditioning or refrigeration systems and can release water mist outdoors. The city’s current guidance does not identify ordinary building plumbing as a source of risk in this investigation.

Who should seek medical care

People who live or work in the affected South Bronx area, as well as anyone who visited since late August, should contact a health care provider promptly if symptoms develop. People with symptoms should not wait for cooling-tower test results before seeking care.

Symptoms can include fever, chills, cough, difficulty breathing and muscle aches. Legionnaires’ disease can resemble pneumonia or another flu-like illness and is treatable with antibiotics when diagnosed early.

People at higher risk include adults 50 and older; people who smoke or vape; and people with chronic heart, lung, kidney or liver disease, diabetes or weakened immune systems.

Tap water and air conditioning remain safe

Legionnaires’ disease is not contagious and is not generally spread from person to person. Under current city guidance, residents can continue drinking tap water, bathing, showering, cooking and using air conditioning.

Window air-conditioning units and other systems that do not recirculate water and release mist are not cooling towers and do not create the same Legionnaires’ disease risk, according to the Health Department.

The city began distributing information in multiple languages on September 11 and scheduled community outreach and town halls through the weekend of September 11-13. Additional case counts, laboratory results and cooling-tower findings may change as the investigation develops.

Sources

• NYC Health Department: South Bronx Legionnaires’ disease cluster announcement
• NYC311: Legionnaires’ Disease
• Gothamist: South Bronx Legionnaires’ cluster kills 1, sickens 5