In the course of two weeks, as many as 18,000 people could have been exposed to a bacteria that causes Legionnaires' disease.
Guests who stayed at the Aria Resort and Casino on the Las Vegas Strip between June 21 and July 4 are the ones in danger of having been exposed to high levels of the bacteria. Officials say water levels tested in several of the hotel rooms between the June and July dates tested positive for the bacteria.
So far, the Centers For Disease Control say six people have come down with the sometimes deadly form of pneumonia. All six have recovered.