Dwarven Atom Smasher

From DwarfFortressWiki

The Dwarven Atom Smasher is a euphemism for a Drawbridge in waste disposal or militarily-significant applications.

As of Dwarf Fortress version 27.176.38c, any creatures or objects (excluding some demons) in a drawbridge tile will die and be destroyed utterly when the drawbridge is raised, provided they have no-where to go when the bridge forms a wall when it becomes raised, IE, the drawbridge's wall fits seamlessly against walls, locked doors, and possibly requiring a floor or wall tile above the tile where the bridge-wall is formed.