Following the disaster of Hurricane Katrina in New Orleans, people began to discuss and visualize the ways in which the urban structure of the city could be reorganized. Rather than defining the disaster recovery process as simply a matter of rebuilding the existing city, these voices called for a more radical rethinking of the city s physical, social and environmental systems. This idea of disaster as an opportunity for urban restructuring is a hallmark of a "design moment."

Design moments are different from the incremental process of urban growth and development. Instead of gradual...