Source: Brannigan's Building Construction for the Fire Service
Venting a fire, even at the risk of increasing its volume, is often necessary to make the conditions inside the fire building somewhat habitable for occupants and fire fighters.
This was recognized over a hundred years ago in the case of multi-story fires in tenements in New York. Packed with hundreds of immigrants, these buildings were deathtraps. A single wooden stairway with wood and glass doors to tenant apartments, rose through the center of a building. Fire fighters learned early on that opening the roof over the stairway relieved the pressure on the upper floors, where potential victims were often at the windows.
In 1903. the New Law Tenement House Act required, among many improvements, that all stairways be masonry enclosed and noncombustible, and have a skylight, so that the fire fighters could easily vent the stairway.