The unit was ambushed and came under Taliban fire from all directions. In the heat of the battle, 22-year-old Giunta did something almost unimaginable.
President Barack Obama described what happened that night at a White House ceremony three years later as Giunta stood ready to become the first living recipient of the nation's highest award for valor in combat, the Medal of Honor, since the Vietnam War.
"Sal sprinted ahead, at every step meeting relentless enemy fire with his own. He crested a hill alone, with no cover but the dust kicked up by the storm of bullets still biting into the ground. There, he saw a chilling sight: the silhouettes of two insurgents carrying the other wounded American away -- who happened to be one of Sal's best friends. Sal never broke stride. He leapt forward. He took aim. He killed one of the insurgents and wounded the other, who ran off."
But almost immediately Giunta felt the weight of the honor. And last week, he took another extraordinary step. At a ceremony in Vicenza, Italy honoring the storied history of the brigade, Giunta pulled out his medal and handed it to the brigade, saying he wanted the medal to be with them: "I want this to stay here in Vicenza, Italy with the 173rd to the men and women that earn this every single day through their selflessness and sacrifice," he told the audience, which was full of young troops.
The brigade's leadership was moved by the gesture: "The first thing that came to mind is like, 'Are you sure you want to do that?' And he said 'yes,'" Sgt. Major Frank Velez told CNN. "There was a few gasps in the crowd and it was folks just going wild. 'That is incredible. This just really happened.'"
But for Giunta it was something he deeply felt he wanted to do. "I am not here because I am a great soldier. I am here because I served with great soldiers," he told the crowd.
The tale of what happened that night has become stuff of Army legend even in the 173rd, which is one of the most decorated units in Army history.
But even in 2010, just before the White House ceremony, Giunta continued to feel the grief and pain of what happened in the valley. "That whole time frame lasted, I don't know two minutes, three minutes, five or six lifetimes, I don't know," he recalled.
While Giunta managed to rescue his badly wounded friend, Sgt. Joshua Brennan, back from the insurgents, Brennan ultimately succumbed to his injuries.
In 2010, Giunta told CNN, "I'll think about it and it hurts. But to say it out loud makes it that much more real, and I feel like I've said enough. I know it's real but sometimes I can trick myself and not think about it for a while."
Now a decade on, the medal will be on display with the troops of the 173rd Airborne, exactly where Salvatore Giunta wants it to be.