Transcript for 'The Long Road Home' with the soldiers and families of Black Sunday
Reporter: A pile of bloody boots. This is what remained after a battle that would take eight American soldiers' lives and leave dozens wounded. Almost undescribable. Probably the loudest thing I've ever heard. Fair came from the right-hand side of the street and the left and the front and the rear -- Reporter: April 4th, 2004. One of the first ferocious battles with insurgents during what was supposed to be a reconstruction mission for the 1st cavalry division. 18 soldiers and their interpreter pinned down in an alley in the slum of sadr city in Baghdad. The rest of the battalion racing to rescue them. Unprotected. Exposed. Facing masses of armed militiamen. We see the Charlie company truck just like the one we were riding in, rode down the road to us, four flat tires. Engine on fire. Wounded. It was shocking at first to see these battle wounds. The best word I can come up with is it was just like a tidal wave. Reporter: In the wake of that tidal wave, those dozens wounded, eight dead. At almost exactly the se time the shooting began -- Reporter: We've been reporting on this story since 2004. Only a few images of the battle existed then. But the soldiers' memories have echoed for us through the years. When you go to a veterans ceremony and you see the old veterans get together and hug and cry, you never really understood it. I understand it now. Reporter: And we understand that feeling today. 13 years later. This is just extraordinary. To see the flags and to see -- Reporter: When we returned to sadr city in a way -- These should be basically a match to the real buildings right here. Reporter: Here at ft. Hood, painstaking reconstructions of sadr city. A hollywood-caliber set for a "National geographic" miniseries. We're rolling! Reporter: Based on my book about the battle "The long road home." Come on, baby. Reporter: There is heart-pumping action. But also the heartbreak of the families of the fallen. Who were invited to the set to see the recreation. This is so hard. Tell me what the hardest part is today. Just remembering and wishing he was here, not that he was in a movie, right? Yeah. Just feeling my emotions again. I know. I love you. I love you. Reporter: Actress Kate bosworth is playing Gina, wife of Troy, one of the wounded in the battle. Your legs just kind of go weak. It's just an unbelievable feeling of fear. It's always to keep in mind that we are telling the stories of heroes. That includes the troops but it includes their families. Reporter: It's a responsibility for the actors portraying these real-life heros to get it right. Jeremy Sisto, playing salve sergeant Robert miltonberger -- How are you? Nice to meet you. Reporter: Asks his real-life counterpart to walk him through that horrible day. Is there moments that you have like, maybefy turned to the left as opposed to the right? No, no. The guilt is that I didn't get shot, and they did. That's it. Reporter: He's not alone. So I was scared to start on this project. It's a lot easier now. Reporter: Aaron fowler, he was shot multiple times trying to rescue his fellow soldiers. Now he's a technical adviser for the miniseries. Let me close a chapter in my life that I didn't get to before. Maybe it opens one too. It does, and that's another thing too. I honestly -- a year ago, I was inpatient for depression suicide. I did not think my future held any more opportunities compared to war and combat and everything like that. Here I am a year later and everything's different. Reporter: The gravity of the role weighs heavy on Michael Kelley, who is playing then-lieutenant colonel Gary valeski. Please bring my baby home. I promise you, every man is coming back safely. How can you promise that? Because I believe that too and because it's my responsibility. We wanted to -- the men who did this in real life, the justice that they deserve. So I think that part is really special. That's what I think the heart and the care comes from. Reporter: The man Michael Kelley is portraying now a three-star general. Gary veleski perfectly captured that heart and care all those years ago. Uncommon valor was common that day. Because there were soldiers doing things that we talk about, but you don't teach stuff like that. You can get them to that point, but where they go in combat wherwhen those rounds are being directed at them, how they react, you know, no one knows until it happens. And they all just performed magnificently. So, you know, I'm honored to be able to serve these soldiers like that. Reporter: For "Nightline," I'm Martha rad dates in ft. Hood, Texas. "The long road home" can be seen on Tuesday nights on national geographic.
This transcript has been automatically generated and may not be 100% accurate.