A growing Legionnaires’ disease outbreak in London is increasingly pointing toward a familiar and well-documented source: cooling towers. According to the UK Health Security Agency (UKHSA), eight confirmed cases have been identified with identical bacterial sequence types, with 13 additional cases under investigation. This combination—genetic matching across cases and absence of a single identified exposure site—is highly consistent with aerosol dispersion from one or more contaminated cooling towers. The Key Clue: Identical Biological Strain Public health investigators rarely get a clearer signal than this: All confirmed cases share the same strain of Legionella Individuals were exposed across different locations in…