Health officials in New York City confirmed two additional deaths linked to a Legionnaires’ disease outbreak on Manhattan’s Upper East Side, bringing the total fatalities to three. The first death was reported last Friday, followed by the death of an 88-year-old man announced on Sunday. That evening, Dr. Alister F. Martin, the city’s health commissioner, confirmed the third death, though further details were not immediately provided.

The outbreak has affected 74 people since early July, with most requiring hospitalization. According to the Department of Health and Mental Hygiene, all but eight patients have since been discharged. Legionnaires’ disease is a severe form of pneumonia caused by the Legionella bacteria, which thrive in warm, stagnant water environments such as those created by rooftop cooling towers during summertime.

Authorities have identified and addressed cooling towers in the Upper East Side as the likely source of the outbreak. Seventy-six buildings in the neighborhood were ordered to clean and disinfect their cooling systems. Officials believe the bacterial source has been eliminated following the cleanup.

Ronald Katter, an attorney representing the family of the second victim, described the deceased as a retired businessman and Air Force veteran who had been married for 50 years. The man was hospitalized on July 2 after his wife found him with a high fever at their East 70s residence. Katter noted the family’s preference for privacy and did not disclose any identifying information.

Legionnaires’ disease cases typically rise during the summer months in New York City, as warm weather increases usage of air-conditioning systems. Cooling towers continuously recirculate warm water, creating an environment conducive to bacterial growth. Fans in these towers can disperse contaminated water droplets into the air, which may infect people who inhale the mist.

While most individuals exposed to Legionella bacteria do not become ill, those aged 50 and older, as well as people with weakened immune systems or chronic health conditions, are more vulnerable to developing the disease.

Health officials have reported a decline in new cases in recent days. “We have not identified anyone with new symptoms for more than a week, and we are not seeing any concerning trends in emergency department surveillance data,” Dr. Martin said. The city continues to monitor the situation closely to prevent further infections.