Legionnaires’ (or Legionella) Disease (LD) is a type of pneumonia that people catch by inhaling small droplets of water suspended in the air containing the Legionella bacterium. There is no evidence of person-to-person transmission. Outbreaks occur from purpose- built water systems where temperatures are warm enough to encourage growth of the bacteria, e.g. in cooling towers and vaporative condensers. Thirty different outbreaks were officially registered in the world between 1976 and 2017. In total 3178 people were affected by the LD, 236 of whom died. The fatality rate ranged between 0.8% and 75% depending to the outbreak. A LD outbreak happened in Palmanova, a touristic neighborhood part of the municipality of Calvià, Spain, between September and October 2017.