Dynamited levees? Floodwall sabotaged? Was the flooding intentional?

Last week, the fever swamps were rampant with rumors of explosions designed to flood the poorer sections of New Orleans with the intent of saving the richer areas. Some no doubt came up with even wilder allegations. Here are some links:
The Xeni Jardin, DailyKos master thread
The LGF response thereto.
Any0ne? MSM Labor Day night,-Locals say explosives opened 9th ward levee
GetYourActOn: Also heard that part of the reason our house flooded is they dynamited part of the levee after the first section broke - they did this to prevent Uptown (the rich part of town) from being flooded. Apparently they used too much dynamite, thus flooding part of the Bywater. So now I know who is responsible for flooding my house - not Katrina, but our government.
Blasts heard before levee broke
Lots of stuff
"Genocide in New Orleans"
UPDATE:
This site ties it all together: the 1927 intentional flooding and the WSJ article about the well-to-do.
And, moderately well-known blogger Ernie the Attorney passes along a letter from the boyfriend of a friend (aka, BFOAF).
And, in the strangest of them all file, try to find this entry on nola.com:

It's not in google's cache. I even saved off their complete archives and grepped, without success... Have shadowy forces gotten to the Times-Pic?