I know it may be a longshot, but could the few adults who are present ask these boys for help in projects to rebuild? Ask them what they would like to see done and give them a space to do it in, like a park, a vacant building or something where if they decide to be destructive instead they would not be harming those trying to pull their lives back together? I've done that with the hang-abouts around here and they may moan at first, but what begins half-hearted and negatively commented on, when they realize it is theirs, they benefit from it and they see results, they get right into it. I always start with a couple bucks or a meal in exchange for carrying something or moving something. Then they decide something else could be done, can they do such and such?
As I said, it may not be an immediate success, or even ever one, but I've seen it work with teen boys here who do drugs, steal, have been in jail, are up all night, kicked out of school, etc. I'm sure it's on a larger scale there, but even one group will relieve the whole. And I think you've got the grit to take no shit while showing compassion: nice does not mean sucker or lack of street smarts. It takes a tough cookie to handle a tough cookie.