Shortly past daybreak on the morning of October 23, 1983, a Mercedes truck tore through the concertina wire that surrounded the U.S. Marine barracks in Beirut, Lebanon.  The truck was loaded with PETN explosive wrapped in compressed gas cannisters.

Inside the four-story Battalion Landing Team headquarters and barracks — colorfully known as the “Beirut Hilton” — some 350 American troops still slumbered. It was Sunday; a day of rest.