fire escape
A fire escape is a kind of emergency exit that is usually mounted to the outside of a building— They may be inside but in an area separated from the main building. They consist of a number of horizontal platforms, one at each story of a building, with stairs or ladders connecting them. The platforms and stairs are usually made of open metal gratings in order to prevent the build-up of ice, leaves, and snow— They may be made of concrete instead, especially if they are indoors.
They provide a method of evacuation in the event of a fire or other emergency that would make the stairwells inside the building inaccessible. They are most commonly found on multi-story residential buildings.