Transcript for Real-life French train attack heroes on recreating incident for '15:17 To Paris'
take down on the train. The man has opened fire on a train travel from Amsterdam to Paris. Three people reported wound. A train flying through the French country side at 200 miles an hour a knife-wielded man armed with an a krks.47 and rounds and rounds of ammo inside. I tried to shoot them. And three young men managed to thwart the attack. I looked over to Spencer and said let's go. Stone seen here with the bare back suffering a knife wound as he subdued the attacker. Brought down before he could kill and maim. I was ability to grab him again and choke him unconscious while Al E C was hitting him in the head. It was do or die. With their childhood buddy they were touring Europe on vacation, ordinary men suddenly called to greatness. Three friends now hailed as international heroes. They hog tied the alleged terrorist, beat him to submission, he's still awaiting trial. The three young Americans the French president gave them a medal and they met the American president. They were all over our TV sets. Those are the same people the real people the actual young Americans played themselves on screen in director Clint Eastwood's "1517 to Paris". I went through casting process and met characters but more I met them something about their camaraderie and three guys growing up together and said wonder if these guys could do it. And they did. Lot of people thought it would be traumatic and now coming to an end with him behind the camera is priceless experience. Casting the real people is kind of executive decision only Clint Eastwood could make. I'm sure people at the studio were saying this is a terrible idea. Oh, I'm sure they did. Eastwood is famously sparring direction not much direction not many takes. Spencer doesn't look like he needs a lot of attention. That's what my teacher said. They all grew up in southern California not exactly model students in school. And we're back in sac. Have you gone back to that school. No never. We avoid it at all cost. We must be can quite proud of you. We have an interesting relationship in history with that school. Alex is here for the hometown screening. Did it make you more scared about what he went through. Yeah it makes me catch my breath when you see it and the tragedy that could have happen that day. And Anthony's parents also here. I thought they did very well. Still unusual two and half years later seeing them on big screen. The boys all attended church. Anthony's dad is the pastor. The dev devil sent those confused terrorists but didn't know what god had. Are you old enough know what it is to be in a Clint Eastwood film. They wrote a book they got to Eastwood but they didn't want to act. We thought you want us to reenact it for the actors. They didn't take much persuasion. It blew our minds, we're like Clint Eastwood thinks we can do it might have to do it. Only other war hero Murphy playing himself in "To hell and back" in 1959. Said have to take acting classes but he said no then it will look like you're acting. It was almost like living it twice but not nearly as scary. We're on the same train, it's moving, you know. There's same amount of blood. And me and mark both kind of got lost in it. I forgot everyone was there until I heard Clint say cut or that was enough and I kind of was like O hrks. Oh. What we'd like to get across is anybody can do something like this. Everyone's capable it's just choices. Our choice was around the fact we didn't want to die that day. They are in fact out of the service and all appeared on who wants to be a millionaire and Alec got far on dancing with the stars. We felt like our lives weren't supposed to be regular didn't know what that meant. Were you concerned that in the public eye you'd become a target. Yabsolutely. Because you were attacked in a bar. Outstandiide a bar. Trying to make it sound more respectful. He was stabbed just months after the train incident. Was that connected with this. Not at all. They didn't know who I was. Just ran into some bad guys. His attker pled guilty and is now behind bar buzz the movie doesn't touch at alternate on their live noise. I almost wanted to see Alec on dancing with the stars and Spencer getting stab the outside of the nightclub as part of the movie. I did too but wasn't relevant. Catapulting tours the. Right now catapulting this hang over. They were just regular guys doing extraordinary ordinary thing. Brace for impact. Common theme was sully landing the plane on the Hudson is saving 155 lives or American sniper. The word hero I hate to use because it's so over used. You become a eagle scout you're way hero. But these three are real heroes and now want to become actors. We want to Tak these lessons we took from Mr. Eastwood can't wait to depict a character. For professional actors it's much harder to play yourself because you're used to hiding behind characters. There's definitely insecurities we had to get over. Now relishing telling their story. You're getting plenty of attention guys. Getting pampered by make up artists and stylists. Hanging with Clint. People think we're a boy band. It's been fun. I'm Nick for "Nightline" in Los Angeles.
This transcript has been automatically generated and may not be 100% accurate.