A new fire-door lock
The fire-doors can be pedestrian single or double-doors, which are supposed to be always closed, except in case of emergency …
… or big sliding gates in underground car parks:
These gates are generally left opened, and automatically close (with a counterweight system), in case of fire. This separates different areas of the car park, and prevents for the fire to take proportions.
Of course, some little pedestrian doors are available for human security.