The death in the world, will perform in SAO "game to life could not be dampened, resulting in the actual body of the players died because of the waves, microwave, from the brain to the game immediately.
SAO death in the world to make a break in the game to not be able to revive it. Then the actual cause of death for microwave players sent to the brain from the game immediately.
Death in the world SAO will figure in game design cannot be revived. And the true form of players died because of microwave from the game, sent to the brain.