(The Waldorf is currently part of the Hilton hotel group, but I’m not sure if there have been any prominent assassinations there.

Update: Hmm. As of 1999, there had been at least four homicides there, but it’s unclear if any of them qualify as prominent targeted assassinations. See https://www.nytimes.com/1999/03/14/nyregion/man-is-found-slain-at-the-waldorf-astoria-hotel.html?unlocked%5C_article%5C_code=1.fk4.atS7.zxI63ob2nybw )