A fifth person has died in connection with a Legionnaires’ disease outbreak on Manhattan’s Upper East Side, the New York City Health Department announced Tuesday evening. The death brings the grim toll from the cluster to five fatalities as health officials continue their investigation into the source of the disease that has sickened dozens in the neighborhoods of Carnegie Hill and Yorkville.
The fifth death came just hours after the city announced the fourth death in the outbreak, marking a rapid succession of fatalities over the past several days. A first death was reported Friday, a second Saturday, a third Sunday, and a fourth Monday, before the fifth was confirmed Tuesday evening. Health officials have not released identifying information about any of the deceased out of respect for their families’ privacy.
The outbreak has grown significantly since it was first identified in early July. As of Tuesday, the city reported 82 confirmed cases of Legionnaires’ disease associated with the cluster, up from 76 cases reported just a day earlier. The disease has affected residents primarily in three Upper East Side zip codes: 10028, 10128, and 10075. Fourteen people remain hospitalized, while many others have been discharged from medical care.
Legionnaires’ disease is a severe form of pneumonia caused by Legionella bacteria that thrives in warm water environments. The disease spreads when people breathe in water vapor containing the bacteria and cannot be transmitted from person to person. Symptoms typically develop between two days and two weeks after exposure and include cough, fever, muscle aches, and difficulty breathing.
Health officials have traced the outbreak to contaminated cooling towers across the Upper East Side. Bacteria have been found in 34 cooling towers at 33 buildings in the affected area. In response, city officials have ordered all buildings with positive test results to immediately drain, clean, and disinfect their cooling towers. Mayor Zohran Mamdani’s administration has taken an aggressive approach to containment, requiring immediate remediation when towers test positive for Legionella bacteria, a faster response than previous protocols.
One of the victims has been identified through his family’s legal representation. An 88-year-old Air Force veteran and retired businessman who lived in Yorkville with his wife of 50 years became ill on July 2 when his wife found him suffering from a fever near an open window in their apartment. After spending two weeks in intensive care, he died. His family has announced plans to sue the owner of the cooling tower determined to be responsible for the outbreak once health authorities complete their investigation and identify the source.
City Council Speaker Julie Menin has been critical of the administration’s handling of the outbreak. She argued that the city moved too slowly in response and that officials should have proactively ordered all building owners in the affected area to clean their cooling towers, rather than waiting for testing results. Menin stated that about 25 percent of the city’s cooling towers were not compliant with testing requirements and should have been disinfected preventatively.
The Mamdani administration has defended its response, noting that it launched an investigation immediately after two confirmed cases were identified on July 2, rather than waiting for the traditional threshold of three cases. Mayor Mamdani emphasized that his administration directed the Health Department to deploy over 100 staff members to begin testing cooling towers across the affected area over the Fourth of July weekend and has taken the unprecedented step of publicly releasing the addresses of all buildings whose cooling towers tested positive for Legionella bacteria.
Health Commissioner Dr. Alister Martin stated that the city believes any source of exposure has likely been eliminated and that no one with new symptoms has been identified in over a week. Health officials continue to inspect every cooling tower that tested positive and are enforcing existing laws to their fullest extent.
The Upper East Side outbreak comes roughly a year after a devastating Legionnaires’ disease cluster in Central Harlem that sickened more than 100 people and resulted in seven deaths. That outbreak highlighted concerns about the adequacy of cooling tower maintenance and oversight in the city. Following that incident, the city implemented new testing requirements, directing building owners to test their cooling towers for Legionella bacteria every 31 days.
Health officials are urging any residents of the affected zip codes who develop pneumonia-like symptoms to seek immediate medical attention and contact a healthcare provider. The city has stressed that tap water, showers, and home air conditioning systems remain safe throughout the affected area. The disease is treatable with antibiotics if diagnosed early, though it can be fatal in approximately 10 percent of cases.