Tonight, my colleague and "world news" anchor, diane sawyer, joins us with the latest in on ongoing abc news series, hidden america. This one, from the streets of chicago. Diane, the powerful report... See More
Tonight, my colleague and "world news" anchor, diane sawyer, joins us with the latest in on ongoing abc news series, hidden america. This one, from the streets of chicago. Diane, the powerful report we're about to see really takes us inside what can only be described as a hidden american war zone. It is true, but we want to say at the outset, as we know, chicago is simply a great city, filled with wonderful people. But as we're going to show you, there are some areas, where small children really do live, as we said, in a kind of battle zone. So, listen to this number. At least419 people were killed this year, across a dozen neighborhoods in chicago, and that is more than all the u.S. Troops killed in afghanistan this year. The cause? Rival gangs, creating anarchy. And, so, "nightline" and "world news" decided to try something different, something unprecedented. We gathered 38 members of rival gangs, past and present, from hispanics to their black rivals, to talk about the slaughter and how to make it stop. Tonight, in america, tens of thousands of childree living in a war zone. One of them is a little boy named ralph. Hey, ralph, it's diane. Ralph is a force of nature. That's it. Reporter: He is also a child who pulled down the blinds in case someone shooting into his living room. I really don't go outside. Just scared, always they going to shoot me or stab me. Reporter: He hears gunshots day and night. You see the alley? Gang bangers running and shooting. Reporter: It was a gunshot that killed his grandmother, who was just standing outdoors. That's my grandma. Reporter: And it says, "rest in peace," for your grandma. We used to eat watermelon a lot and we used to eat noodles a lot. Every time she was going to fix me something, we used to share it. And I loved that. Reporter: So, ralph has a plan to keep his mother safe. On the front door, a gate. A padlock. Bolt. On the back door, bolt, a bike in front of the door, a trash can wedged against that and a chair against the trash can. Inside his fortress, he says, some day, he plans to be a super hero named ralph. And I'm going to change this city into a new city. By taking all the guns out of the city. Reporter: Like the guns that killed 10-year-old julian's big brother, manny. My brother was shot and killed halloween night at a gas station when we went to get a can of coke. Reporter: Your brother was paralyzed? Yes. Reporter: Did you go to see him? Yeah, a couple of times. But my brother, he wasn't healing up right, so, it was a really tough decision for my parents to make, but they decided to let him pass. Reporter: Did they talk to you about it? I remember the day in the hospital, I told my mom, man, i can't wait until manny can come home. My mom said, manny isn't coming home. So, I just wanted to make sure that he knows, I love you, manny. Reporter: They are children growing up in neighborhoods where haunted mothers walk the street, carrying pictures of lost daughters and sons. I keep telling them to stop, they just don't want to stop. They not listening. Where is that coming from? Reporter: Where police is stretched thin. City officials, enraged. Take your gang complex away from a 7-year-old. Who raised you? Reporter: The city is up against 100,000 gang members, young, angry, leaderless, some just 13 years old and carrying a gun. So, we send out word we want to try something different, with the anti-violence group ceasefire, we ask to hold a meeting. Would they come together, would they show up? One by one, they agree to come. Gang members, some in the past, most in the present. They're told to get rid of their weapons. No box cutters, no knives. Reporter: Some of them are seasoned criminals, nearly 90% have been arrested on everything from drug dealing to attempted murder. One, arrested 50 times. He's a member of the hispanic gang two-six. He's called pacman. His friend is puppet. I enjoy fighting. Reporter: There was mr. Blast, from the four corner hustlers. I used to go through shootout, get into altercation with police. Reporter: Jessica, a black disciple, and dre. It is decembusk when 38 of them come to this church on the south side, and is headed by an 'em passioned priest. At the end of the day, we stop the shooting, I'm the happiest man in the world. Reporter: And the head of ceasefire illinois makes it clear, this is an unprecedented event. We had guys from the south side, west side and the latino community. Reporter: People who might be shot if they invade each other's territory, walk in and sit down. Thank you. We know they are suspicious of us and each other. We tell them our purpose. Find one concrete action, that night, that can help stop the violence. There, too, my abc news colleague, alex perez, who grew up in these neighborhoods. And so, the meeting begins. We pose the question -- can it be that there's no way to do something? It's so deep. I don't think anything really can. It's all nothing, really. Reporter: Right away, one by one, they start to tell us, we don't understand, how they are caught up in a vortex of increasing violence. Never going to stop, because it keeps growing like a disease. People are not just shooting to shoot. They shooting, they try to kill you. Reporter: And kill you over something as petty as an insult, a text. Revenge. People do something to one of your friends, you want to do something back. Everybody want to be famous and everybody want to get they name out there and stuff. Reporter: And the biggest name out there is a 17-year-old rapper named chief keef, who is signed by a major record label, interscope. But police say they arrested him for picking a gun on an officer. His youtube video has received 17 million hits. On it, he reminds people they er not talk to the cops. ♪ I will never snitch ♪ ♪ none in my life ♪ Reporter: And remember, he's talking to kids who say they can get guns as easy as a bag of chips. How many here think they believe that they could be a, that voice, to try to put somebody in check, say, man, you don't want to do that. Reporter: But not everybody does. If you are going to go shoot somebody and I step in your way and you real heated, like, you want to shoot them, you probably going to shoot me to get out your way so you can get to the next what would happen if you waited an hour? It could be your last hour. You ain't got time to think. You going to be the prey or What? The prey or the predator. Which one are you going to be? Reporter: And when we come back, we take you inside some of their lives outside this room. Help us. Help us try to be better. Reporter: The impassioned into the night. We don't need dia to come up in here and say for us what we need to do as a people.
This transcript has been automatically generated and may not be 100% accurate.