Depends heavily on what you and your players want out of the game. In all the campaigns I've been in the focus has been storytelling and character growth, so having a character die to some random happening would be counterproductive.

There have been situations within those campaigns where we've done things knowing that character death was a possibility, though, and in those cases we've carried through if the dice fell that way. The key is having buy-in from both player and DM on those particular moments of risk. Even a regular combat could turn into one of those if the player decides to press forward into danger.