Just had to copy & paste from Epic fails in Star Wars design:
An unshielded exhaust port leading directly to the central reactor? Really? And when you rebuild it, your solution to this problem is four paths into the central core so large that you can literally fly a spaceship through them? Brilliant. Note to the Emperor: Someone on your Death Star design staff is in the pay of Rebel forces. Oh, right, you can’t get the memo because someone threw you down a huge exposed shaft in your Death Star throne room.