The storage facility is a separate steel$-$framed building with brick walls and a concrete floor. Access is through a small, aluminium roller$-$shutter door, that is kept wide open during the day for easy access. There are multiple light switches by this door. One large, double$-$glazed window is located on either side of the door. There are old filament$-$bulb lights suspended $5$ metres above the floor. Some of the lights are not working as the light bulbs need to be replaced.

Question: Describe how a serious fire might affect the structure of the storage facility.