They knew the levee was weak.

Original soil tests and design documents for the 17th Street Canal flood wall show layers of weak soil under the wall's steel base that investigators believe gave way during Hurricane Katrina, likely causing the breach that flooded large portions of the city.

Army Corps of Engineers officials and the contractors who designed and built the wall were aware of the soft soil and took it into account in their design calculations, the documents show.

That only deepens the mystery about whether the wall breached because of a design or construction flaw, some factor unaccounted for in the calculations -- or was hit by forces beyond its design capabilities.

The lawyers will be all over this. Who would you sue?