According to the recent Errol Morris documentary, Wormwood, (about the CIA's execution of Frank Olson) the original edition of the CIA Assassination Manual described a 13 story fall as a highly effective assassination technique.
So, as in Frank Olson's case a few years later, one has to wonder why James Forrestal was admitted to the 16th floor of the Bethesda Naval Hospital, for treatment of "depression" (oddly, with Sodium Amytal-- a barbiturate-- and insulin shock therapy.)
The Israelis, certainly, disliked Forrestal, for his ardent opposition to the partitioning of Palestine, and, of course, he was also a diehard Cold Warrior.
Alison Weir talks about Forrestal's case at some length in her history of U.S. involvement in the establishment of Israel-- Against Our Better Judgment.