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: