This Sunday, Marines will gather at the Beirut Memorial in Jacksonville, N.C., near Camp Lejeune to mark the day 28 years ago when 220 of their brothers were killed in a terrorist attack in Beirut, Lebanon. Also killed in the Oct. 23, 1983, attack were 18 sailors and three soldiers. It was a bright Sunday morning at 6:22 when a man drove a five-ton truck laden with more than 12,000 pounds of TNT straight into the base of the building and…