Everything Went Dark

Tatum noticed that the room below the restrooms, the door in the back of the kitchen, the staircase, and any exit was blocked. No exit or entry.
There are 16 dorm rooms.
There are three Lab rooms: Lab A, Lab B and Lab C.
There is one kitchen.
There is one dining room.
There is one laundry room.
There is one trash room.
There is one gymnasium.
There are two restrooms, one for males and one for females.
There is one entry foyer.
However, in the hallway that leads to the entry hall, there is a door that is crossed off from the map. That must be where they go.