You know a player character is going to die next session, mainly thought the stupidity of his actions (I would have to fudge too many dice rolls for him to survive). You know your player is likely to leave the group if his character dies. What can and should you do to prepare the player and make sure they don't leave the group?
Just an update: Unfortunately we've already had the session and as expected his character died. He stormed off from the table and hasn't responded to our emails or phone calls. Unexpectedly the other players in the group are happy he's gone. So it has all worked out for the best I guess, but I'm sure some other DM will have this question one day.
My answer is go ahead and kill the char and let the player leave the group.