The tour buses rolling through the Lower 9th Ward do not stop.
They meander past weedy lots where torrents of water from breached levees shaved blocks of houses off their foundations on Aug. 29, 2005.
Nearly 2,000 people died along the Gulf Coast, mostly from the flooding, which reached attics in some areas. The flood damaged or destroyed thousands of homes and affected 80% of the city. (The tourist-attracting French Quarter, where most of the tour buses originate, did not flood, and its iconic buildings remain intact.)
From ground level in the Lower 9th, a scattering of residents and the construction workers struggling to build back the community might look up and see the tourists, who have paid $40 or so for a "Katrina Tour."
If the bus includes a savvy guide, the passengers' gazes may be directed to another type of visitor, those volunteers on the ground working with one of the dozens of nonprofits tasked with bringing displaced families back home.
Though many other places in the country need volunteers to recover from disasters too, New Orleans presents a compelling gumbo of history, architecture, food, music, joyousness and diversity, along with an awareness that it was that it was not the Category 3 hurricane (which missed the city) that caused all this suffering, but a government-created engineering failure of the levee system, along with the ecological decimation of the wetlands that have historically protected the crescent-shaped city from Gulf storms.
The number of volunteers swarming into the city since Katrina is impossible to calculate. At Habitat for Humanity in New Orleans, 89,000 volunteers have shown up, some many times.
One cold autumn day, Habitat volunteers Bruce Davis, 62, and Kevin Wright, 46, from New Jersey, built stairs leading up to the porch of a lavender-colored cottage that will house the LeFlore family by early January.
Davis knew well the charms and challenges of the city after attending the New Orleans Jazz & Heritage Festival for more than a decade. "I get New Orleans," Davis said. "It's a nice place, and it's not too far from the United States. You don't need a passport."
After he retired as a mental health worker, Davis, from Pennsylvania, and his wife moved to New Orleans a year ago. She got a job, and he signed up to work a week with Habitat. Nearly a year later, he's still at it, working Tuesdays through Fridays and soaking up the region's culture on the weekends.
Wright, on the other hand, had never been to New Orleans before. But when his work as a contractor dried up in New Jersey, he felt a strong pull to fly down to New Orleans to help. "I love doing construction," he said, "so it doesn't seem like work to me."
After his workweek ended and just before flying home, Wright got a chance to try grilled oysters in garlic and butter at Acme Oyster House, savor chicory coffee and beignets at Café du Monde, marvel at the raucousness on Bourbon Street and buy T-shirts for his wife and two kids. His main regret: that his wife wasn't there for the weekend.
Besides individuals, many groups volunteer too. One day in November, the 185 volunteers who signed up with Habitat included 35 from a school in San Diego, 40 from an Elderhostel and 30 members of the Navy.
In neighboring St. Bernard Parish, east of New Orleans and adjacent to the Lower 9th Ward, 90 nuns from several states worked on houses being rebuilt by the nonprofit St. Bernard Project, whose co-founder Liz McCartney was CNN's 2008 Hero of the Year.
In November, the touring cast of "The Color Purple" came to volunteer for the project. Previously, by passing the hat for 14 weeks during nationwide performances, the cast gathered $320,000 in donations. According to St. Bernard Project co-founder Zack Rosenburg, a former Washington, D.C., lawyer and professor, that's enough to buy materials for 29 houses.
The need is great. Nearly all the homes in St. Bernard Parish were damaged or destroyed by flooding, and because the houses were protected by the federal levee system, flood insurance was mostly not required. Many whose homes succumbed received little or no insurance money. Some policies paid for damage above the flood-water line, which meant money for a new roof.
A few months ago, Anne Molsa, a Finnish journalist and university student, incorporated a few days of volunteer work with the St. Bernard Project into her eight-week tour of the United States, figuring this was another way to get to know the country.
Molsa, 23, partnered with a Baptist group from North Carolina, and together they applied drywall to the house of Lynette Harvey, a mother of three whose husband died of brain cancer in 2004.
During Molsa's days at the house, Harvey came by and told the group about getting caught by the storm at work, her evacuation to Houston, and her separation from family and friends. "Such bizarre and touching stories I have seldom heard," Molsa said.
But it was the time that Molsa, a white atheist, spent with her nine African American co-workers, attending their evening devotions, that she called "one of the most interesting things that happened to me in the U.S."
When asked whether she had advice for others wanting to volunteer, Molsa wrote in an e-mail from Helsinki: "Don't be afraid to join the project by yourself, as I did. It is very easy to get to know people while working together, so I bet you won't feel lonely."
Ultimately, Rosenburg and McCartney want to work themselves out of a job. They look to the day when all families who want to come home have a home to come back to.
When will that day be?
"Not any time soon," Rosenburg said. "Not any time soon."