An unidentified U.S. marine looks skyward from his trench during an artillery and mortar attack on the Con Thien outpost near the DMZ in Vietnam, October 14, 1967. The sandbag revetments around the deep trenches offer relative security from shell fragments and flying shrapnel but direct hits during many days of attack have caused many casualties. The base is only two miles south of the demilitarized zone. (Photo by AP Photo)
