I never want to jump to conclusions here, but Dunn Twittered a picture of himself drinking with friends hours before the crash, as he was celebrating a late birthday. Last week was a busy week for him, as Jackass 3.5 was released on DVD, he appeared on the show Minute-to-Win-It alongside (27 months-sober) Steve-O, and he just began a new Mythbusters-ish show on G4.
People have been saying for years they wouldn't be surprised to see a Jackass member dead. Steve-O and Bam both nearly died to drug overdoses. But Ryan Dunn always seemed like the one most grounded in reality. Sure, there was that time he almost killed Johnny Knoxville in a golf cart, but he was always the most normal and perhaps the most likable member. He was also the most famous of the crew, as far as non-Jackass things went, after the show ended.
So remember kids, Dunn didn't die doing a Jackassy thing. He died the same way that hundreds of normal people die each day. Be careful out there.