Modern Marvels: During WWII, American tank crews duked it out with Nazi Panzers in a high-explosive duel to the death. The German tanks had thicker armor and better guns than the mainstay of the U.S. armored forces, the M-4 Sherman. For many crewmen, the Sherman lived up to its nickname as a steel coffin. But what the tanks lacked in firepower and protection, the crews made up for in guts and good old-fashioned Yankee ingenuity. We'll meet some of these armored warriors from WWII.