He displayed conspicuous gallantry and intrepidity above and beyond the call of duty when an American roadblock on the Ormoc Road was attacked by a group of enemy tanks. He left his covered position and, with a rocket launcher and six rounds of ammunition, advanced alone under intense machine-gun and 37-mm fire. Loading singlehandedly, he destroyed the first tank, killing its occupants with a single round. As the crew of the second tank started to dismount and attack him, he killed one of the foe with his pistol, forcing the survivors to return to their vehicle, which he then destroyed with a second round. Three more hostile tanks moved up the road, so he flanked the first and eliminated it, and then, despite a hail of enemy fire, pressed forward again to destroy another. With his last round of ammunition he struck the remaining vehicle, causing it to crash down a steep embankment. Through his sustained heroism in the face of superior forces, Pfc. Vlug alone destroyed five enemy tanks and greatly facilitated successful accomplishment of his battalion's mission.