ATLANTA (AP) - Health officials are investigating an outbreak of Legionnaires' disease apparently centered at a northwest Alabama nursing home. Eleven lab-confirmed cases have been seen in the Florence area. Another eight pneumonia illnesses are being investigated as possibly also Legionnaires'. The Alabama Department of Public Health released details of the investigation Wednesday. No one has died, but two were hospitalized. Legionnaires' disease is a bacterial infection that can cause deadly pneumonia. It does not spread from person to person. Instead, people get it from inhaling contaminated mist or vapor. Tainted shower water, air conditioning systems or whirlpool spas are among the ways bacteria get in the air. The source of the current outbreak is not yet known, but at least eight of the cases have been living at a Florence nursing home.