When the door opened after landing in Da Nang, it was like opening an oven, the heat was a blast right in the face. It was that and sand fleas and combat on his first night there, remembers Bob Atkinson. He was a Marine rifleman, but then he was picked at random and told, "You're a mortarman." Never having seen, much less fired a mortar during training, he wondered, "Are we laying block and brick for these people?" (6:31)