Katrina Mea Culpa

The U.S. Army Corps of Engineers issued a 6,113-page report last week to explain why its hurricane-protection system in Louisiana failed during Katrina. In brief, here's what it said:

Why did the levee system fail? The Corps's system suffered from faulty design that was based on outdated scientific data. The network of canals and levees, built piecemeal over 40 years, was constructed to withstand relatively weak hurricanes, not the Katrina-size monsters that scientists had more recently warned of.

Why didn't the backup protection work? The pumping system meant to mitigate post-hurricane flooding worked at just 16% of capacity during the storm....