The workers have nothing to gain from this war, but they stand to lose everything that is dear to them.
Since the industrial revolution, cities, and especially the inner cities, were the places for the newly arrived. Voluntary immigrants seeking economic betterment, refugees, the bohemians, the artists - all of those people were crammed into densely populated neighborhoods and tenements. And as people climbed up the economic ladder they moved out, which really accelerated with the "white flight" phenomenon in the '60s and '70s.