WASHINGTON  In the most dangerous valley of the most rugged corner of eastern Afghanistan, a small rifle team of airborne soldiers fell into an insurgent ambush, a coordinated attack from three sides.

A young Army specialist, Salvatore A. Giunta, took a bullet to the chest, but was saved by the heavy plates of his body armor. Shaking off the punch from the round, he jumped up and pulled two wounded soldiers to safety, grabbed hand grenades and ran up the trail to where his squad mates had been patrolling.

There, he saw a chilling image: Two fighters hauling one of his American comrades into the forest. Specialist Giunta hurled his grenades and emptied the clip in his automatic rifle, forcing the enemy to drop the wounded soldier. Still taking fire, he provided cover and comfort to his mortally wounded teammate until help arrived.

“It was one of the worst days of my life, and when I revisit it, it kind of guts me a little bit more every time,” the soldier, now a staff sergeant, said Friday.