NEW YORK (AP) – Four patients at New York-Presbyterian Hospital/Columbia University Medical Center were treated for Legionnaire’s disease last month and two of them died, apparently from other causes, the hospital said Thursday.

“There is no information available at this time connecting their deaths to Legionella,” New York-Presbyterian said in a statement.

The state health department is investigating the cases and has not confirmed the causes of the two deaths, department spokesman Joe DiMura said.

The medical center said Legionella bacteria was identified in the water supply of its Milstein Hospital Building. No other buildings at the medical center were affected, and no other confirmed or suspected cases have been reported, it said.

Legionnaire’s disease is treatable with antibiotics and does not generally pose a threat to the public.

The hospital said the four patients who contracted Legionnaire’s had been admitted “in an advanced stage of complex disease,” but it did not elaborate.

Hospital officials said they have taken several steps to guard against future cases, including hyperchlorinating the water, superheating the water system and installing a silver/copper ionization system.

The hospital declined to release any information about the patients. The Daily News reported Thursday that one of the fatalities was a man from Tarrytown, in Westchester County, who died April 13 and the other was an unidentified patient who died March 17.

Legionnaire’s disease is a form of pneumonia caused by a bacteria that occurs naturally in water.

It is spread through the air but not person to person. Most people exposed to it never get sick, but the elderly and people with weak immune systems can be susceptible.