As an engineer, I understand that this could become a real possiblity once they start pumping out the water. Right now, the pressures on the levee system are close to the same on the canal side as on the "populated" side, since the populated side is flooded. Once pumping starts and the water is lowered on one side, those levees whose foundations have been weakenen could easily give way.
There's also the possiblity that no real breach would occur, since there is always some amount of foundation saturation.
I suspect the COE is reviewing the as-built construction plans of the levee system to determine where the potential exists for any type of foundation failures once the pressures on the levee walls again become unequal.
I wonder if anyone will drive their Chevy to the levee...