We all remember Bobby Kennedy was assassinated in June in California

Hillary Clinton apologizes over Robert F. Kennedy remarks
By Glenn Thrush, Newsday
May 24, 2008
WASHINGTON -- Hillary Rodham Clinton on Friday invoked the June 1968 assassination of Robert F. Kennedy to defend her decision to remain in the presidential race until at least June 3 -- sparking a wave of condemnation by Barack Obama's supporters.

Clinton quickly expressed regret for the unprompted reference -- interpreted by many in Obama's camp as a suggestion that she thinks Obama's life might be in danger.