At least two cases of Legionnaires' disease have been identified at the Veterans Administration Medical Center.

A hospital spokesman said Friday that two victims are in the hospital's surgical intensive care unit. Both reportedly are heart-transplant patients.One of the patients - William "Tink" Badget of Sheridan, Wyo. - was listed in critical condition. His family said "his new heart is showing no signs of rejection," but Legionnaires' disease is compromising his respiratory system.

VA Hospital officials Friday morning did not know the extent or cause of the outbreak.

Legionnaires' disease is a form of pneumonia named after a 1976 outbreak that caused the death of 29 members of the American Legion attending a convention in a Philadelphia hotel.

The bacterium breeds most readily in warm, moist conditions; in most outbreaks, the source of infection has been the water or air-conditioning system.