In the article Turning Character Deaths in D&D Into Deals that Benefit Game and Story, David Hartlage (DM David) points out an interesting quote from Gary Gygax in the DMG on Character Death. (The whole post is worth reading, as are many of his others.)
I went looking for the quote so I could give a more complete reference for it. (PDF versions of old gaming books are wonderful!)
In the first edition AD&D Dungeon Master's Guide, on p. 110, in the section “Conducting the Game”, subsection “Rolling the Dice and Control of the Game”, Gary Gygax wrote:
Now and then a player will die through no fault of his own. He or she will have done everything correctly, taken every reasonable precaution, but still the freakish roll of the dice will kill the character. In the long run you should let such things pass as the players will kill more than one opponent with their own freakish rolls at some later time. Yet you do have the right to arbitrate the situation. You can rule that the player, instead of dying, is knocked unconscious, loses a limb, is blinded in one eye or invoke any reasonably severe penalty that still takes into account what the monster has done. It is very demoralizing to the players to lose a cared-for-player character when they have played well. When they have done something stupid or have not taken precautions, then let the dice fall where they may!
On a side note, every time I read the original DMG I'm amazed at everything that Gygax managed to fit into that book. Of course, when I read the three booklets of original D&D I'm amazed at what he managed to fit in those as well.