A somewhat sad coincidence exists between Robert T. Lincoln and attempts to assassinate United States Presidents.

He declined an invitation to accompany his parents to the nearby Ford's Theater the evening his father was shot by John Wilkes Booth on 14 April 1865. He was in the White House sleeping and was informed just before midnight of the tragedy.
While serving as President James A. Garfield's Secretary of War, he accepted an invitation to go to the Sixth Street Train Station in Washington, D. C., with the President. He was an eye witness when the President was shot by Charles J. Guiteau on 2 July 1881.
Lincoln was invited by President William McKinley to attend the Pan-American Exposition in Buffalo, New York. He was present — but not an eye witness — when the President was shot by Leon F. Czolgosz on 6 September 1901.

Future invitations to similar events were declined by Lincoln, who is said to have refused with the statement, "No, I'm not going, and they'd better not ask me, because there is a certain fatality about presidential functions when I am present."

Robert Todd Lincoln