You would have to look back to the fall of Rome for a spectacle of urban collapse to rival Detroit over the last sixty years. The city’s population, which brushed the two million mark in 1950, is now barely seven hundred thousand and falling. Depopulation and economic decline have created a desolate landscape of burned-out businesses and busted houses sagging in on themselves around open roofs and vacant windows. Whole districts have reverted to grassland, with a few fortified homesteads and useless fire hydrants to mark where bustling neighborhoods once stood. Looming over the urban prairie are the vast, crumbling