My reaction to this is one word: shock. This I did not see coming. One moment i'm casually channel-surfing and the next-moment I see his face posted on one of the cable news channels....my general reaction to seeing a retired athlete's face on a non-sports channel during the off-season in the sport they play is that whatever happened is never a good thing. Sadly, this is confirmed as they mention about half a second later that Steve McNair was found dead.
Events such as this are stark reminders that life can end even when it is least expected. Tragic athlete endings such as this one are transcendent amongst society whether or not your a sports fan or whether or not you were a fan of either of the teams he played for. In other words, he died way too young.
Can't really think of too much to write on this subject beyond my initial gut reaction.