From a facilities design standpoint:
So do you look at this instance and say, man we need to really up our game in terms of making our schools more like a fortress?
If only one of those two door locks had worked the way it was supposed to have, then either he would have been outside the school building or just trapped in the Halls. He probably could have still done some damage by shooting through the windows, but he would have been an open Target as soon as law enforcement showed up on the scene.
Or, do you look at this and say the more of a fortress that we make, if a guy does make it into the classroom, then it's much more difficult for our law enforcement men and women to make entry and take care of the situation?