It's also a matter of population density. If the people move away, the buildings they leave behind soon start to look like this. There was a documentary on th

It's also a matter of population density. If the people move away, the buildings they leave behind soon start to look like this. There was a documentary on this (with mostly simulated desolation): http://www.imdb.com/title/tt1433058/?ref_=fn_al_tt_2 http://www.imdb.com/title/tt1433058/?ref_=fn_al_tt_2