Load bearing
From KGB Wiki
A load bearing member of a structure is one that carries significant weight apart from its own. Removing a load bearing member results in structural instability. This is seen in the end of certain types of movies and video games, where the removal of the primary antagonist causes the collapse of her lair.
For example, the destruction of the Mother Brain in Metroid triggered the destruction of her base, forcing the valiant Samus to flee. Mother brain was load bearing.