Forbes has an interesting article about ghost towns, or in this case ghost cities, of the future - major world cities that are in danger of losing their status through a vanishing population due to disaster, environmental crisis, or just plain old demographic rot.

Comments
Thank you, that was an interesting article. When were little everything seems so permanent and unchanging, then we grow up and discover that the earth is changing and society is changing.
Living in Sacramento, I can believe that San Francisco is shrinking, although probably not as fast as Elk Grove would make you think. I wonder what the demographics of the change are. Who leaves the bay area and who stays. Without any research, I would guess that the moderately wealthy population is living in the valley but working in the bay area still.
This was a very fascinating article. Economics seem to hold more clout than natural disasters when people consider a change of scenery. Thanks for the link.