The levee was blown up about 10PM tonight.
First portion of levee breached at Birds Point - KFVS12 News & Weather Cape Girardeau, Carbondale, Poplar Bluff
And this article talks about the Morganza and Bonnet Carre spillways:
Army Corps decides to blow up Missouri levee - Yahoo! News
For background articles, see the postings in the Upper Mississippi flooding thread, which was getting too long.