A fourth person has died in connection with an outbreak of Legionnaires’ disease in New York City, according to city health officials, hours after the mayor said the source of the illnesses appeared to have been eliminated.

There were 76 total cases confirmed by the New York City Health Department, with seven people still hospitalized as of Monday evening. The fourth death came a day after the third fatal case had been confirmed; it was the fourth consecutive day a death had been reported.

Questions continued to swirl among Upper East Side residents Monday, even as city officials believe the Legionnaires’ outbreak may be now under control three weeks after the legionella bacteria were first confirmed in the neighborhood.

“We believe we have now eliminated the source of exposure. Regardless, we will continue to inspect cooling towers and aggressively enforce health laws,” Mayor Zohran Mamdani said. “I’m heartbroken by the loss of my fellow New Yorkers and send my deepest condolences to their loved ones.”

Over the weekend, an attorney for one of the victims, an 88-year-old man, said the victim’s wife found him suddenly ill.

“It wasn’t as if he has an acute illness that he was suffering for. He was sitting in his apartment by an open window and reading a magazine, and when she came home, he had a 104-degree fever,” attorney Ronald Katter said.

Legionnaires’ disease is a form of severe pneumonia caused by a type of bacteria that thrives in warm, stagnant water. Health officials have focused on testing cooling towers that are part of air conditioning systems for large buildings. Property owners have been ordered to drain and disinfect towers where there has been a positive test result.

“I want to reassure New Yorkers they can use tap water, bathe, shower and cook and use air conditioners at home,” said Mamdani.

Legionnaires’ disease is treatable, but 10% of people will die due to complications from the illness, according to the U.S. Centers for Disease Control and Prevention.

Last year, seven people died and more than 100 were sickened during an outbreak in Harlem.

“We advise anyone who has spent time in the three affected ZIP codes — 10028, 10075, 10128 — to seek medical attention if they develop flu-like symptoms, as Legionnaires’ disease symptoms can appear up to 14 days after exposure,” the statement added.

“We will continue to keep New Yorkers updated on the details of this investigation. The most up-to-date information is available on the Health Department’s website.”

Sources: https://www.nbcnews.com/news/us-news/four-dead-legionnaires-osourcepanpdlocnatnbcngennbcnews-rcna588503