Legionnaires' Disease Cases Surge in Manhattan's Upper East Side

WHO:

NBC News - The Guggenheim Museum is among the sites affected by the outbreak of Legionnaires' disease.

West Side Rag - The Ardsley is an Art-Deco building with more than 200 units, constructed in 1931.

WHAT:

Fox News - Health officials reported 23 confirmed cases and 17 hospitalizations related to the outbreak.

NBC News - The Guggenheim Museum was not shuttered at any point due to the positive test or remediation work.

NBC News - The city health department confirmed that there is no additional action needed at this time, and this poses no risk to anyone inside the Guggenheim Museum.

AP News - The Guggenheim Museum was among 19 buildings that have already completed the remediation process for their cooling towers, with the remaining buildings expected to finish by Saturday.

AP News - The city health department reported that there are currently 54 confirmed cases of Legionnaires' disease connected to the Upper East Side cluster.

AP News - More than 50 people have been diagnosed with Legionnaires’ disease in connection with the Upper East Side cluster, with less than 20 remaining hospitalized.

AP News - No deaths have been reported in the current outbreak.

NBC News - The city Health Department released a preliminary list of buildings with cooling towers that tested positive for Legionella for the first time.

Gothamist - 19 of the buildings have completed the process of cleaning and disinfecting their contaminated water-cooling towers.

Gothamist - Owners of 19 of the buildings have already completed the process of cleaning and disinfecting their contaminated water-cooling towers.

NBC News - 31 cooling towers in Manhattan's Upper East Side have tested positive for Legionella bacteria.

West Side Rag - The Ardsley’s hot water system tested positive for Legionella bacteria.

West Side Rag - There are 54 confirmed cases of Legionnaires' disease connected to the Upper East Side cluster.

West Side Rag - The Health Department reported that Legionnaires' disease is not contagious and cannot be contracted through drinking water, cooking, or using air conditioning.

WHERE:

NBC News - The outbreak is occurring on Manhattan's Upper East Side.

West Side Rag - The Ardsley is located at 320 Central Park West, between West 91st and 92nd streets.

WHEN:

West Side Rag - The disinfection and flushing of The Ardsley’s hot water system is scheduled for Thursday, July 16.

WHY:

West Side Rag - The increased attention to Legionnaires' disease in New York City may have prompted The Ardsley to conduct an independent evaluation of its hot water system.

HOW:

AP News - The city health department emphasized that the positive test results do not confirm any of the buildings as the source of the outbreak, as the tests conducted could not distinguish between live and dead bacteria.

AP News - The city health department stated that the positive test results do not confirm any of the buildings as the source of the outbreak, as the tests could not distinguish between live and dead bacteria.

West Side Rag - The evaluation for Legionella within The Ardsley’s hot water system was conducted independently by the owner, not by the New York City Health Department.

West Side Rag - The Ardsley has retained Metrogroup, a qualified water-management consultant, to assess its domestic hot water system.

(UPDATED July 12, 2026 11:16 UTC)

Health officials have reported 23 confirmed cases and 17 hospitalizations related to the outbreak. The Guggenheim Museum remains open, with the city health department confirming that no additional action is needed and there is no risk to anyone inside. Meanwhile, the disinfection and flushing of The Ardsley’s hot water system is scheduled for Thursday, July 16.

(UPDATED July 12, 2026 07:44 UTC)

The Guggenheim Museum is one of 19 buildings that have completed the remediation process for their cooling towers, with the remaining buildings expected to finish by Saturday. Meanwhile, the city health department has reported 54 confirmed cases of Legionnaires' disease linked to the Upper East Side cluster. However, officials stressed that the positive test results do not identify any of the buildings as the source of the outbreak, as the tests could not differentiate between live and dead bacteria.

(UPDATED July 12, 2026 01:20 UTC)

More than 50 people have been diagnosed with Legionnaires’ disease in connection with a cluster on the Upper East Side, with fewer than 20 individuals still hospitalized. Fortunately, no deaths have been reported in this current outbreak. The city health department has indicated that the positive test results do not confirm any specific buildings as the source, as the tests are unable to differentiate between live and dead bacteria.

(UPDATED July 11, 2026 22:15 UTC)

The city Health Department has released a preliminary list of buildings with cooling towers that tested positive for Legionella for the first time. Of those, 19 buildings have already completed the cleaning and disinfecting process for their contaminated water-cooling towers. Notably, the evaluation for Legionella within The Ardsley’s hot water system was conducted independently by the owner, rather than by the New York City Health Department.

(UPDATED July 11, 2026 20:15 UTC)

Owners of 19 buildings have successfully finished cleaning and disinfecting their contaminated water-cooling towers. This important step comes as part of ongoing efforts to ensure public safety and maintain health standards. The work was reported to have been completed by 20:15 UTC.

(UPDATED July 11, 2026 19:20 UTC)

The Guggenheim Museum is among the sites affected by an outbreak of Legionnaires' disease, with 31 cooling towers in Manhattan's Upper East Side testing positive for Legionella bacteria. The Ardsley, an Art-Deco building located at 320 Central Park West, has also reported that its hot water system tested positive, contributing to a total of 54 confirmed cases linked to this cluster. To address the situation, disinfection and flushing of The Ardsley’s hot water system is scheduled for Thursday, July 16, and the building has hired Metrogroup, a qualified water-management consultant, to assist with the assessment.