as soon as you get out of the hall with the baracaded doors a teleport opens up infront of that hall, that's maybe 15 feet away from the path the humans take.
Guess what happens when a mass of zombies go throught it that while people are not paying attention to the left side of the path.
Edit: Valve AND Zero would find a way to screw up a steel ball.
I have never seen any other server that used to be so much fun to play on just get so properly rammed into the ground by one person's lazyness, incompetence and inability to grasp how to properly run a server.