From the New York Times:
"The Census Bureau reported on Thursday that 343,829 people were living in the city of New Orleans on April 1, 2010, four years and seven months after it was virtually emptied by the floodwaters that followed the hurricane.
The numbers portray a significantly smaller city than in the previous census, in 2000, though it should be said that New Orleans had been steadily shrinking even then. In 1990, it was the 24th-biggest city in the country, in 2000, the 31st, and now it has surely dropped from the top 50."
Smaller New Orleans After Katrina, Census Shows
February 3, 2011