Note: This is the first in a series of items about New Orleans, based on a just-finished visit to the city.

I’ve spent the last forty-eight hours trying to think of an image that conveys what I saw in New Orleans last week. But the best I can do is a pair of images, both from the Lower Ninth Ward, that together capture the contradictions and complexities of the city five years after Hurricane Katrina.

A few blocks north of one of the neighborhood's main thoroughfares is a single-story house with a fresh coat of grayish-blue paint. The lawn is bursting with green grass, recently cut. The small garden near the entrance has blooming violet flowers. It is not a large house. The narrow “shotgun” footprint can’t have space for more than five rooms, including a kitchen. But it has all the tell-tale signs of recent construction and would seem utterly unremarkable in plenty of middle-class neighborhoods.

Just a block further to the north is a lot full of overgrown vegetation. It's one of dozens in the immediate area, but this one caught my attention because of four concrete stairs rising out of the ground, presumably where a front porch or stoop once stood. As you get closer, you can see some more concrete, laid flat on the ground, with weeds sprouting up through what used to be the sections of a driveway. But otherwise the lot is empty.

You could think about the new house, the one with the fresh blue paint, and say it’s proof that life and prosperity are returning to the Lower Ninth, which Katrina had so utterly and famously devastated. You would have a point. Thanks in part to construction by Habitat for Humanity, Brad Pitt’s “Make It Right” project, and other non-profits, clusters of new houses are forming near the levees that separate the community from downtown New Orleans. Some of the older homes remain, too--and some of their owners have done impressive work restoring them. The Lower Ninth may have been a poor neighborhood, certainly by national standards, but it was also a stable community with deep roots. Before the storm, more than 60 percent of residents owned their homes, well above the citywide average. Many of these people have since returned.

But you could also look at that empty lot, or the many more like it, and say it’s proof that the Lower Ninth is in deep trouble. Again, you would have a point. Overall, just 25 percent of the residents have returned--the lowest percentage in all of New Orleans. Retail is virtually non-existent; the closest grocery store is at least a fifteen minute drive away. The neighborhood also lacks key services. If you have a heart attack in the Lower Ninth Ward, the closest hospital is in downtown--across a draw bridge. “I feel like my neighborhood has been forgotten,” says Vera McFadden, president of the neighborhood council.

And such ambiguities aren't confined to the Lower Ninth Ward.  Earlier this month, the Brookings Institution published The New Orleans Index at Five, arguably the most comprehensive survey you’ll find on the state of the city. And if you assume (as I certainly had) that the situation in New Orleans is bleak, bordering on hopeless, you’ll be surprised by its findings. City population is back to 80 percent of what it was before the storm. The unemployment level is actually lower than the national average. But for every piece of good news there is bad news, or at least a footnote. The city has grown more affluent, for example, largely because poor people were more likely to leave and never return. New levees are up but replenishment of the wetlands, essential both for the environment and hurricane protection, has stalled..

My visit last week was the result of good fortune: an invitation to speak at a conference. It was also a chance to re-establish a connection I made twenty years ago, while covering news as a summer intern for the Times-Picayune. Many writers call, or have called, New Orleans home and, to be very clear, I'm not really one of them. I spent most of my ten weeks there adjusting to professional journalism and life outside the I-95 corridor, both of which were novel experiences at the time. But I was there long enough to care about the the city and the people in it.

Not that a special connection should be necessary to care about New Orleans. Katrina had a huge political impact, changing popular perceptions of the Bush presidency. But it didn't impress the American psyche with nearly the force that 9/11 did, despite loss of life that was of the same magnitude and devastation that was arguably larger, depending on how you calculate it. I don't mean to draw a moral comparison between two such different events. But I often wonder whether America has forgotten not just McFadden's Lower Ninth Ward but the city as a whole.

I hope not. It's important to understand what happened there, before and after the storm, in order to hold public officials accountable and to avoid similar tragedies in the future. As I toured the city last week, I tried to focus on three questions in particular:

Has the city rebuilt itself? Katrina was the most devastating natural disaster in American history, wiping out not just homes and business but all kinds of public infrastructure. To what extent has New Orleans been able to rebuild that?

Has the city reinvented itself? New Orleans had serious economic, social, and political dysfunction before the storm. Given a chance to start over, could the community build a better city?

What lessons can New Orleans teach the rest of us? The city has become a petri dish for experiments in urban renewal, education reform, health care, and environmental restoration. How are those experiments going?

I don’t have anything close to definitive answers to those questions. The subject is too big and complex. But I have impressions, observations, and a few insights. Over the next few days, I'll tell you what I learned--and introduce you to some of the people I met along the way.