The week's news at a glance.
Civil engineers investigating the flooding of New Orleans now believe some of the citys levees may have failed due to poor construction. Initially, it was widely assumed that the hurricanes storm-surge had pushed water levels over the top of the flood barriers, and in eastern regions of the city this appears to have been the case. But some of the other levees bear high-water marks, like a ring around a bathtub, suggesting the water never climbed high enough to overtop the levees, but rather broke through by undermining the levees foundations. If confirmed, the finding could open the city up to massive lawsuits from displaced former residents.