SYRACUSE - A 13th person has come down with Legionnaires' disease and health officials say the bacteria that causes the deadly respiratory ailment has been found at a second location, a Syracuse nursing home.

Investigators searching for the source of the outbreak discovered the Legionella bacteria that causes the illness in the water system of the 526-bed Van Duyn Home and Hospital, said Gary Sauda, the Onondaga County director of environmental health.

Legionnaires' is a severe form of pneumonia. People become infected by inhaling airborne water droplets that contain the bacteria. It can be fatal if left untreated.

So far one person has died since the outbreak began June 30, although health officials said they have not yet confirmed Legionnaires' was the cause of the person's death.

Investigators suspect the outbreak was caused by Legionella bacteria discovered in one of the air conditioning cooling towers at Community General Hospital, but they have not yet proven it. Six of 13 people infected were Community General patients.

In Legionnaires' outbreaks, people up to two miles away from the source can be infected. The nursing home and hospital are located less than a half mile apart.

The staff at Van Duyn is working with state health department officials to minimize risks to the nursing home's residents, Sauda said.

On Wednesday, officials at Community General reported that their first effort to kill the Legionella bacteria in its cooling towers two weeks ago did not work. The hospital performed a 24-hour disinfection process July 4.

The hospital received test results Tuesday showing the bacteria was still present.

At that point, the hospital had already carried out a second 48-hour disinfection process over the weekend, following federal Centers for Disease Control and Prevention guidelines, said Tom Quinn, the hospital's president and chief executive officer.

Test results from the second cleaning may not be available for two weeks, he said.