A fourth person has died in connection with the Legionnaires’ disease outbreak on Manhattan’s Upper East Side, city health officials confirmed Monday evening, just hours after Mayor Zohran Mamdani announced that the source of the illnesses appeared to have been eliminated. The death marked the fourth consecutive day a fatal case had been reported in the cluster, which has now grown to 76 total confirmed cases. Seven people remained hospitalized as of Monday night. The mayor expressed sorrow over the mounting losses while striking a cautiously optimistic tone about the trajectory of the outbreak, which began three weeks ago when legionella bacteria was first detected in the neighborhood.
Mamdani told reporters that officials believe the source of exposure has been eliminated but pledged continued inspections of cooling towers and aggressive enforcement of health regulations across the area. “I’m heartbroken by the loss of my fellow New Yorkers and send my deepest condolences to their loved ones,” he said. He also sought to reassure residents that everyday activities remain safe, saying New Yorkers can continue using tap water, bathing, showering, cooking, and running home air conditioners without concern.
Among those affected was an 88-year-old man whose case has drawn particular attention. His attorney, Ronald Katter, said over the weekend that the man’s wife found him suddenly ill with a 104-degree fever after returning home to find him sitting by an open window reading a magazine just moments before. “It wasn’t as if he has an acute illness that he was suffering for,” Katter said. Legionnaires’ disease is a severe form of pneumonia caused by bacteria that thrives in warm, stagnant water, and health investigators have focused their testing on cooling towers connected to large building air conditioning systems. Property owners have been ordered to drain and disinfect any towers that tested positive.
The CDC notes that while Legionnaires’ is treatable, roughly 10 percent of those infected die from complications. The current outbreak echoes a similar crisis last year in Harlem, where seven people died and more than 100 fell ill. City health officials are urging anyone who spent time in ZIP codes 10028, 10075, or 10128 to seek medical attention if they develop flu-like symptoms, noting that signs of the illness can emerge up to 14 days after exposure.