Design flaws seen in broken La. levees

NEW ORLEANS, Oct. 24 (UPI) -- Evidence is mounting the August failure of Louisiana levees and flooding of New Orleans after Hurricane Katrina was caused by U.S. military design flaws.

Findings based on physical evidence, Army Corps of Engineers documents and hydrodynamic models run through a Louisiana State University supercomputer show two of three levees collapsed when weakened soils beneath them became saturated and began to slide.

The findings also confirmed that a little-used navigation canal helped amplify and intensify Katrina's initial surge on Aug. 29, contributing to a third floodwall collapse on the east side of town.

The Washington Post said experts now believe Katrina was no stronger than a Category 3 storm when it came ashore.

"This was not the Big One -- not even close," said Hassan Mashriqui, a storm surge expert at LSU's Hurricane Center. He said that Katrina would have caused some modest flooding and wind damage regardless, but that human errors turned "a problem into a catastrophe."

The floodwall failures left about 100,000 homes underwater and caused most of Louisiana's approximately 1,000 hurricane deaths.