NEW ORLEANS (AP) — Seven years ago, the Army Corps of Engineers was desperately trying to plug breaches in the city's broken and busted levee system.

Since those catastrophic days, the Army Corps has worked at breakneck speed to install new floodgates, pumps, floodwalls and levees across New Orleans. The work paid off. A day after Isaac hit New Orleans on the seventh anniversary of Katrina, officials said the 130-mile flood protection system did its job.

Tim Doody is the president of the commission that oversees the levees. He gave the system an A-minus.

The only problem came at the 17th Street Canal, the site of a breach during Katrina. When computers that are supposed to turn on pumps failed there Wednesday, pump operators had to turn them on by hand.