Image CDC
In a follow-up on the Legionnaires’ disease outbreak linked to the Sheraton Atlanta Hotel, the Georgia Department of Public Health (DPH) reports 11 lab-confirmed cases of Legionnaires’ disease and 55 probable cases of Legionnaires’ disease related to this outbreak through July 29.
No deaths have been reported.
Probable cases are people who had illness consistent with Legionnaires’ disease, including pneumonia diagnosed by a clinician or chest X-ray, but without laboratory confirmation. The number of probable cases can change based on additional testing and lab results.
Since the first cases of Legionnaires’ disease were confirmed two weeks ago, epidemiologists from DPH and Fulton County Board of Health (FCBOH) have been reviewing hundreds of survey responses from individuals who stayed at or visited the Sheraton Atlanta between June 12 and July 15, 2019. The surveys help identify people who may have been ill, especially those with severe illness like pneumonia.
FoodWorld 
What was the source
I am sure that it has been confirmed, probably a water cooling unit or air con