GARDEN CITY PARK, N.Y. (CBSNewYork) — A Legionella scare has struck a popular gym in Garden City Park, Long Island.

As CBS2’s Jessica Layton reported, at least two people whose lab tests were sent to the Nassau County Health Department, confirming Legionnaire’s disease, said they visited the Garden City Park LA Fitness.

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The health department ordered the gym to close its pool and spa area after two water samples tested positive for Legionella bacteria.

That letter sent to members two days ago also now hangs in the window of the gym. It says in part: “We are asking any members who utilized the pool area in November or December 2016 and who are experiencing signs of illness to contact their healthcare provider and inform them of their potential exposure.”

Legionnaire’s often mimics the symptoms of pneumonia or even cold or flu, so it can be hard to diagnose. Signs include a cough, shortness of breath, high fever, muscle aches, headaches, chills and diarrhea.

As the Nassau County Health Department points out, an infected person will usually start showing those symptoms two to 10 days after exposure, and the disease can be serious.

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“Legionnaires disease can be very serious,” said Mary Ellen Laurain of the Nassau County Health Department. “Approximately one in three people who develop Legionnaire’s disease are three hospitalized. In New York state, we see about 200 to 800 cases a year.”

Laurain noted that the disease is not spread from person to person, but is found in water sources such as hot tubs, pools, cooling towers, and hot water heaters.

LA Fitness said customers who have used other gym equipment such as weights or cardiovascular machines, but have not used the pool and spa area, likely need not be concerned.

As 1010 WINS’ Sonia Rincon reported, some gym members were not deterred.

“I’m still coming. I have to you know? I cannot be sitting home,” one man said.

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The pool and spa area will be decontaminated and will be closed until the health department returns for a new inspection.