The vast grid of streets here in New Orleans, laid out long ago on grassy bottomland near a waterway, remains eerily devoid of houses. Modest bungalows were ripped from their moorings by the foul, murderous floodwaters of Hurricane Katrina three and a half years ago. Eventually, the storm-tossed homes were torn down and carted away. Today, cinderblock foundations dot brush-covered lots like archeological remains. Live oaks line sidewalks upon which no one walks to school, or rides a bike, or runs to the corner store.