hat it is easier and safer to transport people from an unsafe to a safe area than to transport resources into a disaster area. He suggests outfitting disused military bases as a network of evacuation centers, equipped in advance with water, food, medical supplies—even buses. "The infrastructure to support fixed evacuation sites might or might not be more costly than a single lengthy aid operation under the current approach for a single disaster, such as Katrina," Dr. Nusbaum writes. "Use of multiple sites would make it likely that wherever in the country a disaster struck, an evacuation site would be relatively close by and fully intact."