William Frawley, who played Fred Mertz on "I Love Lucy," lived at the hotel for decades. On March 3, 1966, he was coming back to the Knickerbocker when he dropped dead of a heart attack on the sidewalk in front of the hotel. His nurse dragged him into the lobby in an attempt to revive him, but it was too late.
He lived at the Knickerbocker and was returning home so he was always in that area. The Grateful Dead played at the Ivar two weeks before. No word yet on whether Frawley was a Dead Head.