According to civil engineer Rutger De Graaf, in the event of a hurricane or flood, a floating city might be the safest place to be. In fact, he envisions self-sustaining cities in the middle of the ocean. He runs the firm that designed a pavilion of floating, connected geodesic domes in the port of Rotterdam. Sometimes design problems have to be worked out. This video from NOVA Online shows other buildings that are out of balance.