Over the last three weeks, I've played the original Halo trilogy in its entirety. My main impression is that the life of the Master Chief would be much longer if architects in the Halo universe incorporated the basic safety rail into their work.
Now, sure, Master Chief is seven feet tall and weighs quite a bit in his armor, and yes there are occasions when, under my guidance, he has jumped off cliffs or bridges or buildings of his own free will or carelessness. Still, a basic OSHA inspection of USMC or Covenant facilities would turn up glaring omissions of basic safety precautions.
(And from a game-player's standpoint it's real drag to have to replay a tough level just because you accidentally walk off a bridge when you're not looking.)