fire escape      
noun [ C ] uk/ˈfaɪər ɪˌskeɪp/ us/ˈfaɪr ɪˌskeɪp/
 (尤指建筑物外用以逃离火场的)太平梯
a set of metal stairs, especially on the outside of a building, that allows people to escape from a burning building
 - More examples
 - As smoke billowed out, people were clambering down the fire escape at the back of the building.
 - In the event of a fire, make your way immediately to the nearest fire escape.