Which bit? The rooftops in the East End? Because that's where I live and the trees here are too young. The city neglected the neighbourhood badly for decades because (a) it was mostly non-white and that's what happened to non-white neighbourhoods in the mid-20thC, and (b) the more it was neglected, the sooner it could be condemned for being rundown (and the blame passed on to the residents) and then bulldozed to make way for freeways. It didn't unfold like that in the end, although some blocks were lost to mega-projects. What's left is now much more leafy, thanks mostly to campaigns by lefty civic politicians and officials in the 1960s and '70s.