1. New Orleans’s levees failed because Katrina was just too big.

This was how the Army Corps of Engineers tried to spin it in the aftermath of the storm. But key levees, including the 17th Street and London Avenue canals in the heart of the city, failed with water well below levels they were designed to withstand.

As the Army Corps eventually conceded, they were breached because of flawed engineering and collapsed because they were junk. Sheet piling — metal planks driven into the ground to reinforce levees and flood walls — didn’t run deep enough. Corps geologists botched tests that should have determined soil stability below the levees. The Corps and local levee boards that maintain flood barriers pinched pennies, and suddenly Katrina became the nation’s first $200 billion disaster.

 

2. The state response was as bad as the federal one.

As criticism of President George W. Bush and his FEMA chief, Michael “Heckuva Job” Brown, spread, the White House began trying to shift blame to local authorities, chiefly Louisiana Gov. Kathleen Blanco (D). The rap was that she had taken too long to declare a state of emergency and then failed to make clear her state’s needs.

In fact, Blanco had declared a state of emergency on Friday, Aug. 26, one day before Mississippi’s Republican Gov. Haley Barbour and indeed the White House itself. The following Monday, as Katrina made landfall, she was pleading by phone with the vacationing Bush: “Mr. President, we need your help — we need everything you’ve got.”

Tens of thousands of New Orleanians were trapped in the Superdome and the city’s Convention Center. The Louisiana National Guard had asked FEMA for 700 buses; days later, the agency sent 100, and nearly a week had passed before the last flood survivors were herded aboard.

Another line of attack, playing on the stereotype of the shiftless South, was to imply that the citizenry had been too indolent to get out of harm’s way. “The failure to evacuate was the tipping point for all the other things that either went wrong or were exacerbated,” Brown told Congress a month after Katrina.

In fact, the exodus of an estimated 1.3 million people from southeast Louisiana — roughly 400,000 from New Orleans — was not only one of the largest in U.S. history, but the monumental traffic flow was notably well-lubricated in contrast to previous evacuations.

 

3. The storm gutted the heart and soul of New Orleans, turning it into a majority-white city.

Katrina didn’t turn New Orleans white. According to the 2010 census, the city’s black majority eroded from 67 percent before Katrina to about 60 percent now, in part because of a significant influx of Hispanics. The post-storm city’s no El Dorado, either: Unemployment was at 4.7 percent in June 2008, as the city rebuilt, but stands at 8.1 percent today. And 41 percent of kids in Orleans Parish live in poverty, more than double the national rate.

Racial paranoia and conspiracy theories persist, however, including the conviction that the city’s elite blew up the levees to protect rich neighborhoods at the expense of poorer ones, or to drive low-income African Americans out of town.

This falsehood — cued by inexact memories of a deliberate levee breach in 1927 — gained currency after the storm. Louis Farrakhan claimed that Mayor Ray Nagin told him that the levees had been blown up, a view Nagin felt obliged to disown under questioning on Capitol Hill. And Spike Lee, who would later direct a documentary about Katrina, espoused similar ideas. “I don’t find it too far-fetched,” he said in 2005, “that they try to displace all the black people out of New Orleans.”

The story does not stand up to even casual review. The levees failed so extensively during Katrina that it would have taken scores of dynamite charges detonated simultaneously over many miles of levees to decimate flood defenses as thoroughly. Note also that some of the worst-flooded areas, the Lakeview neighborhood among them, were rich and white.

4. New Orleans’s levees are fixed and could withstand another Katrina.

After Katrina, Washington committed $14.5 billion to flood-protection improvements that are supposed to survive a 100-year storm — a term of art that refers to storms that have a 1 percent chance of striking in any given year.

But here’s the problem: By the Army Corps’ own accounting, Katrina was not a 100-year storm but an even stronger 400-year storm. And it only sideswiped New Orleans. In other words, the Crescent City still lacks a flood defense remotely strong enough to withstand a direct hit by the really big storms — Katrina-size or even larger — that the gulf can whip up.

5. New Orleanians learned their lesson and are more likely to evacuate sooner.

Don’t count on it. Even as storm tracks showed Isaac on target to plow right up the Mississippi, most New Orleanians stayed put — and many a bar stayed open. Here and there across the city, neighbors pulled grills out onto the sidewalk and observed another tradition: hurricane barbecues. After all, anything in the freezer was likely to go bad as soon as the electricity failed.

outlook@washpost.com

Jed Horne is an editor of the Lens, an investigative news site about New Orleans. His books include “Breach of Faith: Hurricane Katrina and the Near Death of a Great American City.”

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On Tuesday, almost seven years to the day after Hurricane Katrina hit the Gulf Coast, Hurricane Isaac made landfall in southeast Louisiana. For those of us who were around for the Katrina catastrophe, there was reason to wonder if seven years of healing was going to be undone in an afternoon. That healing has been impressive: Tourism and business start-ups are on the rise, the school system has been overhauled, and though the murder rate remains appallingly high, public corruption among politicians and police is under siege. But some things remain the same — among them persistent falsehoods about what happened seven years ago and why.