http://www.npr.org/templates/story/story.php?storyId=102384657
I copied and pasted the article, but they have the audio version on their website and I recommend you listen to that instead of reading this.
I heard this on NPR a couple days ago and I found it very interesting. Its a complete breakdown on what happens when the FDIC declares a bank is "Failed" and the 3 day turnover of all assets, computer systems, accounts, money etc. to another bank. They move in like spies or cops about to do a major drug bust.