panic room
noun /ˈpænɪk ruːm/,  /ˈpænɪk rʊm/
  /ˈpænɪk ruːm/,  /ˈpænɪk rʊm/
 (also safe room)
- a room in a home or an office building where people can go to avoid a dangerous situation- The door and walls of the panic room are made of steel.
- The panic room has a secret entrance that is impossible to detect unless you know it is there.