For Americans, the city that neatly packages postindustrial decline (and despair) into one place is Detroit. The Motor City has become shorthand for captialism gone kaput: urban decay, senseless violence.
Unfortunately, there are a number of cities that fit that bill, Camden, NJ, being one of the most inhospitable. In the month of July, 13 peopler were murdered there. Because of the city's size, its murder rate is larger than New York City's (though not Chicago, a place afflicted by awful amounts of crime, this year especially).
No city should become a stand-in for problems the entire country faces. Take inventory of the scope of the situation by turning your attention to Camden.