Before you spawn, go all the way up to floor 28, where the elevator lets out. Just outside of the elevator is a generator. Move it in front of the elevator door. , if the Survivors know what you are doing, they can move it. It will require three survivors to move an object. However if you have someone else on the Infected side, they can go a little bit further and move the forklift that is there in front of the doorway.