From USA Today…

Hurricane Katrina drained nearly 300,000
people from coastal areas between Texas and the Florida Panhandle,
according to new government population estimates that tally for the
first time the storm’s devastating toll on the Gulf Coast.

Katrina also doubled the rate of population
growth in nearby counties, which absorbed tens of thousands of people
the hurricane displaced, the Census Bureau’s estimates show. The estimates for July 1, 2006, being released today, are the first
broad measure of the hurricane’s demographic imprint in the 10 months
after the hurricane waterlogged New Orleans and splintered houses
across Mississippi’s coast.

SNIP

The losses were most pronounced around New Orleans. The city lost half
its population — about 229,000 people — between July 2005 and July
2006. Neighboring St. Bernard Parish lost three-quarters of its 65,000
residents.