Origin of the "Blue Flame" nickname:

For nearly four decades, the building at 815 Mercer St. served as the headquarters for Washington Energy.  On top of the building was a 26-foot neon blue flame sign. It became a Seattle landmark. After Washington Energy merged with Puget Power, the "Blue Flame Building" was sold. The new company, Puget Sound Energy, donated the sign to the Museum of History and Industry.