The Gulf Coast and New Orleans observed the 10th anniversary of Hurricane Katrina in ways both devout and festive.

During an evening celebration Saturday New Orleans Mayor Mitch Landrieu pointed out the ways in which many people doubted the city could — or should — survive. But said that 10 years later New Orleans is still standing.

The storm killed more than 1,800 people and caused tens of billions in damage.

Many of the dead came in New Orleans when levees protecting the city burst, submerging 80 percent of the city in water.

In Mississippi church bells rang out to commemorate the storm's landfall. And dignitaries thanked the hundreds of thousands of volunteers who have come to the coast to help rebuild.