In 1914, in Wisconsin, seven people were murdered at Frank Lloyd Wright's home. To this day, no one knows the real reason for the massacre. 
 Sources:
 https://www.taliesinpreservation.org/history/
  https://en.wikipedia.org/wiki/Taliesin_(studio)
   https://www.history.com/news/the-massacre-at-frank-lloyd-wrights-love-cottage
  https://en.wikipedia.org/wiki/Frank_Lloyd_Wright
  https://centerforinquiry.org/blog/dispelling_a_ghost_at_fallingwater/
 https://www.hauntedillinois.com/realhauntedplaces/dana-house.php
  https://www.architectmagazine.com/design/frank-lloyd-wright-homes-with-haunted-histories_o