By Brian Boyles
New Orleans has observed the 10th anniversary of Hurricane Katrina by remembering the dead and joyously celebrating the Big Easy's comeback from disaster with marches and brass bands.
The city's leaders on Saturday placed wreaths at a memorial to Katrina's unknown victims, marking the hour that the Category 5 storm struck with catastrophic force, overwhelming this Louisiana port's system of levees.
More than 1800 people were killed across the US Gulf Coast when Katrina made landfall on August 29, 2005.
A million people were displaced and the financial toll topped $US150 billion ($A210 billion).
"New Orleans will be unbowed and unbroken, we're still standing after ten years," Mayor Mitch Landrieu said at a solemn ceremony attended by about 400 people on the lawn of Charity Hospital.
"We have risen, and we will rise again, but we can only do it if we hold each other up and we don't leave anybody behind."
The memorial to the unclaimed Katrina victims holds the remains of the scores of victims whose bodies were never identified or claimed.
After the wreath ceremony, the solemnities gave way to parades, marches and partying to cap a week filled with remembrances, conferences, tributes and a visit from US President Barack Obama.
The events commemorate the destruction of New Orleans - and the botched government response to the mounting crisis - which shocked the world.
Some 80 per cent of the low-lying coastal city was swallowed by floods which rose as high as six metres after the coastal city's poorly-built levee system burst from the pressure of a massive storm surge.