How does flash media fail? Graceful, or violent?

bhodge writes: "Aside from the obvious "it stops working" answer, how does flash media — such as USB, SD, and CF — fail? Unlike the traditional hard drive, where anyone who's worked with computers for a while should know what a drive failure looks like, I don't know anyone who's experienced such a failure. I've been able to find more than scant evidence of what flash media failures look like, at the OS level. There just don't seem to be many accounts. The one account I have found detailed using a small USB drive /var/log storage: it failed very quickly, and then utterly (0 byte unformated device), after 5 years of service in the role. This seems to run contrary to other anecdotal claims that you should still be able to read the media after you can no longer write to it. So slashdotters: what have you seen, if anything?"