NEW YORK (CBSNewYork) — A new cluster of Legionnaires’ disease cases was recently diagnosed in the South Bronx, and city officials on Wednesday were investigating the water distribution system in one public housing development.

The Department of Health and Mental Hygiene said the cluster of four Legionnaires’ cases was recently discovered in the Melrose Houses development. The department, along with the New York City Housing Authority, tested the water distribution systems in the buildings.

The water in the building at 681 Courtlandt Ave. tested positive for legionella bacteria, the department said. Two other buildings, at 304 E. 156th St. and 700 Morris Ave., tested negative and results were pending late Wednesday for five others.

The Health Department, in consultation with the Centers for Disease Control and Prevention, decided to turn off the hot water in the Courtlandt Avenue building. Water filters will be installed in every unit in the building to eliminate the bacteria, and the hot water will be turned back on afterward, the department said.

Long-term disinfection plans are also being developed.

Some residents said they should have been told about the problem earlier.

“Disgusting – they’re treating us like we’re nothing. Like, how do you tell people that something’s in their building,” said resident Debra Dobson. “You know, you have an inkling that it’s there, but you are telling us at the last minute.”

A Legionnaires’ outbreak earlier in the summer killed a dozen and sickened over 100 more in the South Bronx, prompting city guidelines for testing and treating cooling towers. The epidemic was traced to a cooling tower at the Opera House Hotel.

Earlier this week, the Convent of the Sacred Heart School on the Upper East Side was closed after testing revealed legionella bacteria in the cooling tower. Classes have not yet started at the school, and no disease cases were reported there.