NEW YORK (CBSNewYork) — The city’s health department says it is investigating three cases of Legionnaires’ disease at Co-op City in the Bronx, including one elderly patient who died.

The Health Department said the cases occurred in three connected buildings at the complex within the last 12 months.

In a statement, health officials said the three patients who became sick had “conditions that increase the chances of getting Legionnaires’ disease.” Two patients have been released from the hospital, according to the department. 

Health officials say they will be sampling the internal plumbing of the building to assess the potential sources of the disease. They say the complex does not have a cooling tower.

“Residents of this building who are over 50 or have underlying medical conditions should avoid showering until the investigation is completed,” the Health Department said, adding that tap water in the building is safe to drink.

Legionnaires’ disease is caused by breathing in water vapor containing the bacteria. It is not contagious and is treatable with antibiotics.

“(Residents) can reduce their risk by seeking care early,” Health Commissioner Mary Travis Bassett said. “It’s a very treatable infection but very often people delay care seeking.”

Symptoms include fever, cough, chills, muscle aches, headache, fatigue, loss of appetite, confusion and diarrhea, officials said. Symptoms typically appear two to 10 days after exposure to Legionella bacteria.

“As always, adults with flu-like symptoms, fever, cough, or difficulty breathing should seek immediate medical attention,” the Health Department said. “Legionella testing should be considered by clinicians based on history, symptoms, and other findings.”

More: Five Facts About Legionnaires’ Disease

As CBS2’s Marc Liverman reported Wednesday, it’s a disease that changed Ronald Hines Jr.’s life forever.

“I asked my mom a few times, ‘Am I dead?’ I didn’t know if I was dreaming or in limbo. It was just a real strange feeling to have that disease,” he said in an exclusive interview.

“He was unresponsive. We thought he was going to die, that’s how bad it got,” his father Ronald Hines added.

At 29 years old, Hines Jr. spent nine days in the intensive care unit after contracting the disease.

“It’s kind of like being in a coma, because I woke up and everything was different,” he said. “I couldn’t speak, I couldn’t walk. I had to write notes on my pad just to communicate with my mom and dad for a while.”

His was one of at least eight cases in Co-op City in 2015. Now, the disease is back.

“It’s very scary, because look at what it can do, look what it has done,” said his father.

Hines Jr. recovered but his speech and stamina still suffer.

His father hopes that health officials will find the source of the bacteria so no one else suffers like his son.

“That no one else succumbs to it,” he said. “Find out where it started and get some resolution, so we don’t have to worry in the future about this recurring.”

The city started regular, mandatory inspections of cooling systems after a deadly Legionnaires’ outbreak in the South Bronx where 12 people died.