NEW YORK / RankWire.AI / – Legionella DNA was found during initial testing of a cooling tower at Yankee Stadium as New York City probes a cluster of Legionnaires’ disease cases in the South Bronx. By Tuesday evening, authorities confirmed 11 cases, including one fatality. Three individuals remain hospitalized. The New York City Health Department identified 10 cooling towers with positive preliminary PCR results across ZIP codes 10451 and 10456, which encompass parts of Melrose and Morrisania.

As part of the investigation, city health officials sampled 24 cooling towers, with 10 testing positive via PCR, including the tower located at Yankee Stadium at 1 E. 161st St. PCR testing detects genetic material from Legionella bacteria but does not confirm whether the bacteria are alive. Since only live Legionella bacteria can cause illness, additional laboratory culture testing is currently underway to determine if viable bacteria were present in the sampled cooling towers.
The Yankees have stated that no confirmed cases within the current outbreak have been linked to Yankee Stadium. The team explained that its cooling towers, installed in 2024, are subjected to regular water quality assessments. According to the Yankees, a Legionella test on Aug. 20 was negative. The team also conducted weekly water quality and bacteriological indicator tests on Aug. 26, Sept. 2, and Sept. 9, prior to the city collecting its PCR sample on Sept. 11.
Cooling towers undergo cleaning following initial positive results
In response to the preliminary positive findings, the New York City Health Department directed all 10 cooling towers to be fully cleaned and disinfected. The deadline set for remediation was Sept. 14. On Tuesday, Health Commissioner Alister Martin confirmed that all towers with concerning positive results had been cleaned and disinfected. The Yankees reported that the Yankee Stadium cooling tower was drained, cleaned, and disinfected on Sept. 13 after the city notified them of the preliminary results.
Legionnaires’ disease is a form of pneumonia caused by Legionella bacteria. Infection typically occurs when individuals breathe in tiny water droplets that harbor the bacteria. The disease does not usually spread through person-to-person contact. Symptoms may include fever, cough, and breathing difficulties. City officials advised those who have lived, worked, or visited the South Bronx area since late August to seek medical attention if flu-like symptoms develop.
Ongoing investigation into South Bronx Legionnaires’ cases
According to health officials, eight of the 10 towers with positive preliminary results complied with the city’s 31-day Legionella testing requirement. The remaining two locations had yet to provide the necessary testing data at the time of the investigation’s announcement. The scope includes cooling towers at Yankee Stadium and other properties in the affected neighborhoods. Authorities continue to analyze laboratory findings and epidemiological data to identify the source of exposure linked to the confirmed illnesses.
The Department of Health stated that residents in ZIP codes 10451 and 10456 can safely continue drinking tap water, showering, and operating air conditioning units unless instructed otherwise. They also emphasized that being inside buildings connected to the 10 cooling towers does not increase risk. The Yankees noted that city health officials have not requested postponement of games at Yankee Stadium. Monitoring of confirmed cases is ongoing, with laboratory work proceeding on samples collected during the South Bronx investigation.
