I'm a bit surprised there hasn't been more buzz about This American Life's two episode profile of Harper High School in Chicago where "last year alone 29 current and recent students were shot." It is, as you might expect, gripping and heart-wrenching.
I particularly recommend the first part, which provides some explanation of the overall situation in Chicago, which can be baffling to even those of us who understand other American cities fairly well. What is happening there that isn't happening elsewhere (yet?)?
In short (as TAL explains it, at least), the structure and leadership of their street gangs has been disrupted and what has replaced it is more decentralized, chaotic, and all-encompassing.