1.
Stair one stops at the top guest room level and goes down to the lower office suites and to the "Pink Hallway"
Stair two goes up to the attic and level (unlocked) and continues to roof and penthouse level (both locked last time I checked) and down to the "Pink Hallway".
Stair three goes up to the freight elevator penthouse (unlocked) and roof access (locked) and down to the Physical plant, Food and liquor (with beer still there) storage, Laundry and housekeeping, maintenance, and telecommunication rooms. The door at the bottom of this stair way is locked only intermittently. Almost all locked doors off the pink hall lead to this same area.
The pink hall (not shown) runs under the main floor hallway, a maintenance corridor runs parallel to it opposite the stairs and barber shop.
All basement Physical plant/ Maintenance/ laundry areas are off limits, So have a cover story and be prepared to hide. These areas aren't well patrolled but there are sometimes employees down there.
The Attic is completely un-patrolled.
The passenger elevators only go down to the pink hallway. The freight elevator goes to the Physical plant, all elevators are usually staffed with an operator.
The rest of the building is mostly open now.
This is about the last chance to see the old place before it is gutted and turned into an office building. 
