NEW YORK (CBSNewYork) — One person who contracted Legionnaires’ disease in the Morris Park section of the Bronx has died, city officials said Wednesday.

Meanwhile, the number of confirmed cases in the neighborhood has grown, from 10 on Tuesday to 13. All have underlying health conditions and contracted the disease before Sept. 21, officials said.

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Eleven people are hospitalized, and one has been discharged.

The city has tested 35 cooling towers in the area — 15 were positive for Legionella bacteria. The city Health Department has ordered those sites to begin cleaning and disinfecting the towers immediately.

Most of the infected cooling towers were on or near area hospitals, 1010 WINS’ Al Jones reported.

“We’re fixing anything that we had concerns about, but I don’t want anybody to be worried about going to the hospital,” City Health Commissioner Dr. Mary Bassett said.

The city is stepping up its community outreach and monitoring to identify other potential cases.

Legionella bacteria in a hotel cooling tower caused an outbreak of the disease in the South Bronx over the summer that contributed to at least 12 deaths.

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Basset has said she doesn’t believe the Morris Park cases are connected to the earlier outbreak.

Mayor Bill de Blasio called the Morris Park outbreak much more limited than the experience they had in the South Bronx in August, WCBS 880’s Rich Lamb reported.

“And every cooling tower that we had any concerns about has been or is in the process of being addressed,” the mayor said.

But Bronx residents want to know why the bacteria keeps popping up in their borough.

“I don’t see why they should not have done it, to get into a situation where they weren’t able to do it. All it is, is a basic cleaning,” said Phil Williams.

New cooling tower cleaning regulations were put in place after that outbreak.

Legionnaires’ disease — a form of pneumonia especially dangerous for the elderly and for people with underlying health issues — can usually be traced to places favorable to Legionella growth such as cooling towers, hot water tanks, whirlpool spas, hot tubs, humidifiers and condensers in large air conditioning systems. The city says its drinking water supply has not been affected.

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It is spread through contaminated mist and cannot be spread from person to person.