carina tells us about an organization that literally races to help. >> i'm very proud of what we did, do it again, i would do it again. ♪ >> those words are especially meaningful when you realize how much staff sergeant de los santos gave for his country. he lost his leg in afghanistan >> it was like -- everything was, like, in slow motion, kind of like being in a movie. and then when they pulled me out of the truck, that's when the pain... that pain... >> after the pain came the questions. his plans for the future seemed shattered. >> you know, i was like, "wow. my life is over. what's going to happen to me?" >> but staff sergeant de los santos didn't give up. he worked hard to regain his strength. and he learned about an organization called achilles international. in greek mythology, achilles was as close to being invincible as any warrior could be. but even the greatest warriors can be hurt. achilles international encourages disabled athletes to compete in marathons and other public events. and they have a special chapter for members of our military. it's called the freedom team of