[Amelia]

I'd hazard a guess that those trees were blown over, the gap where the roots were (and the pulling of the roots) weakened the earth backing of the levee, and when they started pumping all the water into the canal, they created enough pressure to destroy it.

In Georgia, we're told not to have trees on earthen dams for just that reason.

[kingu]

They tell us the same thing in California, but we're also talking about a rather densely settled city and those trees are in backyards of homes. If this does indeed turn out to be the reason, I hope that they go through and deforest the entire levee system there.

Anyway, off to bed I go.