Well, Gentlemen, we have an MMA Death...
Not sure if this the first confirmed MMA Related death or not (if you were to ask Frank Mir, it would be, unless you were to count his chances of ever reaching the top of the Heavyweight Division again as a "death") but it's in South Carolina... where they do things "diff'rently".
Kid died of brain hemorrhage following GnP strikes than knocked him unconscious.
http://www.mmafighting.com/2010/06/28/michael-kirkham-dies-following-pro-mma-debut/