GWEN IFILL: Now, another in our series of profiles of Purpose Prize nominees. The prize is awarded to people who began new social enterprises after retiring. Tonight, special correspondent Fred de Sam Lazaro reports on one man's efforts to help homeless youth.

FRED DE SAM LAZARO, NewsHour Correspondent: In the shadow of San Diego's gleaming downtown, behind the chain link and shrubs, are haunts only a few homeless people know.

RICK KOCA, StandUp for Kids: Hello. Anybody here?

FRED DE SAM LAZARO: And Rick Koca wants to keep it that way.

RICK KOCA: Got some nice candles. I see kids' clothes mostly. It's a kid, at least a couple of kids. I don't necessarily want to say where this place is. I don't want people to come and hurt them or anything else when they're sleeping.

FRED DE SAM LAZARO: Except to the adults who prey on them, Rick Koca says homeless kids are largely invisible in society, even though they number some 1.3 million.

RICK KOCA: If there's one thing that I hear over and over and over, it's, "Oh, my goodness I didn't know there were homeless kids on the streets by themselves. I see the adults. I never see the kids." Well, we don't see the kids -- first of all, we're probably not looking. And then, I don't know what we're looking for. They don't look any different than you or I.

Resources for homeless kids

FRED DE SAM LAZARO: One place you will find them is at the StandUp Center. It's the centerpiece of an organization Rick Koca founded called StandUp For Kids. And, indeed, it's hard to tell homeless kids from volunteers. This is a place to get a meal, toiletries, clean clothes, to check e-mail, play games, get a state I.D., or just get cleaned up.

RICK KOCA: And then the girls have their own shower and their own bathroom. Boys aren't allowed to come down here and use this part.

FRED DE SAM LAZARO: And if only for a few hours, it's a place to be safe.

RICK KOCA: So many couches here, because lots of kids like to come in, just sit down and go right to sleep. They know no one is going to hurt them, no one is going to touch them, or anything else. They don't have to worry about anything.

FRED DE SAM LAZARO: Rick Koca says he's always been involved with helping children. He grew up in a large family in Nebraska, was a scouting volunteer when his own kids were growing up, and also worked in a children's home in Britain, where he was once posted during a 30-year naval career.

When he retired 18 years ago, he started StandUp For Kids to work with homeless children. Last year, StandUp served homeless youth some 58,000 times across the country. Koca discovered early that homelessness was a symptom of much deeper issues.

RICK KOCA: Their issue is, "I'm not homeless. I'm lifeless, and you can't make this worse. You can't shoot me. You can't stab me. You can't rape me and make this situation worse." And I think, as I began to walk the streets and saw that, that was horrible to me that kids didn't care what you did to them. I mean, and lots of people did and do unbelievable things to children on the streets.

And that's why it didn't become about homelessness. It became about helping young people put their lives back together.

So you've been on the streets, on and off, for four years, is that what you said? Since you were 15, but you finished high school. You got a GED or what?

HOMELESS TEENAGER: Diploma.

RICK KOCA: Got a diploma. And how come you're not in city college now, Alex?

Surviving on the street

FRED DE SAM LAZARO: Koca says most homeless kids are bright and resourceful, traits that allow them to survive on the street. We brought our cameras along as Koca visited what they called a squat, an abandoned, boarded-up hotel shared by Alex and two buddies, Jeff and Shadow.

HOMELESS TEENAGER: OK, don't set the house on fire like you did on the other one.

HOMELESS TEENAGER: I didn't set the house -- oh, yeah.

RICK KOCA: And how old are you?

HOMELESS TEENAGER: Eighteen.

RICK KOCA: How long have you been homeless?

HOMELESS TEENAGER: A year.

RICK KOCA: A year. What grade did you finish in school?

HOMELESS TEENAGER: Eighth.

RICK KOCA: Eighth grade. And do you see the point of getting a GED?

HOMELESS TEENAGER: Well, me and Jeff are going to go back to...

HOMELESS TEENAGER: Las Cruces.

HOMELESS TEENAGER: ... Las Cruces, and there we're probably going to go to the college over there.

FRED DE SAM LAZARO: The only electricity here is in the smoke alarm batteries, so the group moved to the upper floors.

HOMELESS TEENAGER: It might be a little bit dirty, but it gives us a roof to sleep over during the nighttime. And then when it rains, it beats sleeping under a bridge in the rain.

I'm like a packrat. I come through here, and I'm like another man's treasure is another man's trash and blah, blah, blah. You know how the saying goes.

FRED DE SAM LAZARO: On this day, Shadow's haul was a concert ticket he got from panhandling.

RICK KOCA: Where's the concert?

HOMELESS TEENAGER: It was the House of Blues.

RICK KOCA: Oh, the House of Blues. And then you went like that?

HOMELESS TEENAGER: I always do.

RICK KOCA: Just curious.

Fleeing abuse at home

FRED DE SAM LAZARO: They have survival skills, Koca says, but not social skills. Many homeless youth are fleeing abuse at home, he says, only to find new forms of it on the street.

RICK KOCA: We know that, in the U.S., a child runs away every minute. Within 48 hours, 50 percent of them return home. Our concern is about the other 50 percent who, according to statistics, 42 percent of them become involved in prostitution just to survive. And it's an equal number among males and females. Therefore, there's four things that you can do. You can prostitute yourself, sell drugs, beg for money all day, or steal.

FRED DE SAM LAZARO: Alex and Jeff admitted they've done all four, including what they call survival sex.

HOMELESS TEENAGER: And me and him -- I'm going to tell them anyways. We were -- and this guy named Uncle Don...

HOMELESS TEENAGER: And Georgio.

HOMELESS TEENAGER: ... and Georgio, basically they're porno producers. Basically what they do is $250 a film.

HOMELESS TEENAGER: Basically, Georgio finds you. You have sex with Georgio, and then he hooks you up with Uncle Don, who's the producer, and who gets you into the porno.

RICK KOCA: So would you consider that the worst thing that you had to do to survive on the streets?

HOMELESS TEENAGER: Yes.

HOMELESS TEENAGER: The worst thing, because I'm not -- that's not my lifestyle. I don't like doing that stuff.

FRED DE SAM LAZARO: Restoring stability to young lives like these is complicated by everything from legal problems to mental illness to family disputes. But beneath the rough exterior, Koca says, is often a strong desire to get out of their predicament.

HOMELESS TEENAGER: Right now, I'm just looking for a job.

RICK KOCA: But you're going to Las Cruces? When you come back and you're ready to look for a job, I'll give you a cell phone and I'll pay for it. If you want to go to school and you need a cell phone, I'll pay for it. And I'll say that to all three of you. We've already given three kids cell phones.

HOMELESS TEENAGER: That can't be a bad deal...

HOMELESS TEENAGER: That can't be beat.

HOMELESS TEENAGER: No, dude, I'm staying here. Forget that. I need a cell phone so I can get in contact with people and I can get in contact with my mom and my job.

RICK KOCA: We're going to get you -- get your GED, back into college, right at city college. Same thing with you. I'll hook you up with some nice clothes. I'll hook you up with a cell phone and hook you up with a lawyer you need and you already know.

RICK KOCA: After you get back into school, I'll buy your books if I have to buy your books. And as long as you keep going, then I'll keep going.

HOMELESS TEENAGER: I have issues that...

RICK KOCA: And that's fine. That's fine.

Programs in 37 cities

FRED DE SAM LAZARO: StandUp for Kids now has programs in 37 U.S. cities. Its annual budget is still under a million dollars, thanks to some 5,000 volunteers.

RICK KOCA: So you can see how many we have in Baltimore, 531; Boston, 790.

FRED DE SAM LAZARO: Large companies that target the youth market have donated the cell phones and clothes, even grants for legal aid. They're small things that kids could expect from a family in normal circumstances. Koca is clear that StandUp cannot do big things, like law enforcement, mental health care, or social work.

RICK KOCA: It isn't about case management. You know, that is a very necessary part, but that's not something we do. You know, it's like we're not the pastor, either, you know? We're not the eye doctor. And we do the family piece.

He says, "Hey, Dad, I got your e-mail, and I'm happy to hear from you."

FRED DE SAM LAZARO: Rick is a father figure to dozens of young people, some who've moved onto stable lives, others, like this one, in prison.

RICK KOCA: And we're not working. We're just volunteers who help homeless and street kids. And we just kind of...

FRED DE SAM LAZARO: At 64, Koca plans to cut back on his hectic schedule. He traveled 197 days last year. But even in this second retirement, he plans to speak out on behalf of the generation of his grandkids. He says 13 homeless young Americans die every day from disease, abuse or suicide.