Abstract: An automatic emergency door closure is provided that can be used with an existing door by inserting a hinge pin assembly into knuckles of hinge plates associated with the existing door. The hinge pin assembly is movable between a first position where the door is held in a regular use position in which it can be opened and closed and a second position where the door is released to a closed position. This movement from the first position to the second position may be as a result of a variety of triggers, including a message transmitted from a remote location or nearby heat. The assembly may include a hinge pin body that is inserted into the knuckles, a torsion spring that is configured to rotate the hinge pin body, and an activator that can be activated by the trigger to enable rotation of the hinge pin body.