Amid seven deaths from Legionnaires' disease in what appears to be New York City's biggest outbreak ever, Mayor Bill de Blasio said Tuesday that his administration and the City Council will soon introduce legislation to help prevent future flare-ups of the disease.

The measures will set "new inspection standards for buildings with cooling and condensing units," de Blasio said at Lincoln Medical Center in the South Bronx, where several victims are being treated and where a cooling tower that tested positive for the disease has been decontaminated.

City Health Commissioner Dr. Mary T. Bassett stressed that most residents are not at risk, but older adults in the South Bronx exhibiting flu-like symptoms should seek care.

"This is the largest outbreak of Legionnaires' disease that we are aware of in New York City," she said. "This is not the time to let an older member of your family say, I don't want to go to the doctor."

Water-based cooling towers, usually hidden from view and differentiated from visible rooftop water tanks, in nonresidential buildings. are likely sources of the outbreak of the noncontagious, treatable form of pneumonia, city officials said.

At least seven people -- all of them older with pre-existing medical conditions -- have died and 86 people have been sickened as part of a rash of infections, officials said.

Bassett said at the news conference that city officials are confident they've identified the primary cooling tower or towers responsible for the cluster of infections in the South Bronx, but await further testing.

She said she expects the infections to wane within a week.