As noted in Morning News, Nancy Leson at the Seattle Times has the details and some of the history, but not the weirdest thing about the place: Seattle lore holds that Ted Bundy worked at this Red Robin when he was a student at the University of Washington. (During that time, Ted Bundy asked my aunt out on a date. She said no because she thought he was too square. Good one, Aunt Jean.)
Over on Facebook, some rabid Red Robin fans have started a movement to keep the place open. There are 59 "devastated" members as of this writing.