The Same thing happened to a friend of mine yesterday, Sam room/ building . We tried a few things to get him but not much worked.. The wall facing the stairs is glitched. You can throw Stuff in and out of the room by Sprinting to the wall with the object in your hands and when you hit the wall press G to throw the object, that will the glitch through the wall. They only way we could get my buddy out was to use a SKS (sure any Rifle will do) go the glitched wall, set the barrel through the wall(just stand close and aim), my buddy stood in front of the barrel and we shot him. It Worked.. He died and spawned. Hope it helps.