Sad story here. Sounds like he was racing and lost control. Seemed like a nice guy on the reality show.
http://sports.yahoo.com/mma/news?slug=ys-mmaweektt031109&prov=yhoo&type=lgns
http://sports.yahoo.com/mma/news?slug=ys-mmaweektt031109&prov=yhoo&type=lgns