Large squeaky metal rolling door closes, footsteps, large squeaky door opens.
A large squeaky metal rolling door closes, footsteps walk down the hallway and another large squeaky door opens. Gentle tapping is followed by a loud bang, complete silence and squeaking wheels rolling down the hall. Large squeaky metal rolling door closes, footsteps, large squeaky door opens. Someone is pushing a large trolley and crashing it before walking and moving another. Tapping with a louder bang followed by complete silence then slightly squealing wheels rolling.