A fifth person has died in the ongoing Legionnaires’ disease outbreak in New York City, health officials confirmed on Tuesday, as authorities continue searching for the source of the bacterial infection that has sickened more than 60 people over the past month.
According to the New York City Health Department, Legionella bacteria have been detected in 34 cooling towers across 33 buildings in Manhattan’s Upper East Side. Officials said all affected cooling towers are currently undergoing cleaning and disinfection as part of efforts to contain the outbreak.
Despite extensive testing, investigators have not yet identified the exact source of the bacteria responsible for the infections.
Health officials, however, noted that no new patients have reported symptoms during the past 10 days, suggesting that the outbreak may be stabilizing.
More Than 60 People Affected
The Health Department said the outbreak has so far affected more than six dozen people.
Among the confirmed cases:
- Five people have died.
- Eight patients remain hospitalized.
- Fifty-six patients have recovered and have since been discharged from hospital.
As part of the response, authorities are cleaning and disinfecting 82 cooling towers located in 80 buildings across the affected area.
What Is Legionnaires’ Disease?
Legionnaires’ disease is a severe form of pneumonia caused by Legionella bacteria, according to the US Centers for Disease Control and Prevention (CDC).
The bacteria thrive in warm water systems and can multiply in places such as:
- Cooling towers
- Air-conditioning systems
- Hot tubs
- Decorative fountains
- Large plumbing systems
People become infected by inhaling tiny water droplets contaminated with Legionella bacteria.
Health experts emphasize that Legionnaires’ disease does not spread from person to person.
Although the illness is treatable with antibiotics, the CDC estimates that it is fatal in around 10% of cases, particularly among older adults and individuals with weakened immune systems.
Luxury Buildings and Museums Among Sites Testing Positive
Investigators have found traces of Legionella bacteria in cooling systems at several buildings across the Upper East Side, including luxury residential properties, private schools and well-known museums.
Among them is the Guggenheim Museum, which said its cooling tower is tested and treated every month by an independent specialist company as part of routine maintenance.
The findings come despite stricter city regulations introduced earlier this year that increased cooling tower testing requirements and expanded inspection efforts.
Attorney Says Outbreak Was Preventable
Texas-based attorney Jory Lange, who represented victims of last year’s Legionnaires’ outbreak in Harlem, criticized the recurrence of similar incidents.
Lange, who is now representing at least three patients affected in the current outbreak, said the situation should have been avoided.
“There’s no excuse for this to keep happening,” Lange said. “New York already has the best and strongest regulations … and yet this still keeps happening.”
The previous Harlem outbreak claimed seven lives and sickened more than 100 people, prompting city officials to strengthen oversight of cooling tower safety.
Health Department Expands Inspection Efforts
New York City Health Commissioner Dr. Alister F. Martin praised the department’s rapid response after the first cases were detected.
He said swift action helped reduce the impact of the outbreak and save lives.
“The department’s quick action after the first two confirmed cases saved lives.”
Martin added that officials would use the findings from the ongoing investigation to strengthen public health policies and reduce the likelihood of similar outbreaks in the future.
Following last year’s Harlem incident, New York City approved the hiring of 23 additional Legionella-focused water ecologists and supervisors, increasing the planned workforce to 56 specialists.
The department currently has 35 staff members in place, while 14 additional recruits are undergoing training and field orientation. Recruitment continues for the remaining positions.
Officials also reported a significant increase in inspections, completing nearly 1,600 cooling tower inspections during the first six months of the year—a 35% increase compared with the same period in 2025.
As the investigation continues, health authorities remain focused on identifying the outbreak’s source while ensuring contaminated cooling systems are disinfected to prevent further infections.