The present invention provides device that replaces the hinge pin in a door hinge to provide a door with automatic closing technology, triggered by the device's detection of an adverse condition in the surrounding environment, such as a fire or gas leak, the device including a lower extension pin that slides into the space conventionally occupied by the hinge pin, first and second arms that apply opposing rotational force to the door and door jam, respectively, when the device is activated, and a condition detection module employing at least one sensor and an activation system to activate the device upon the sensor's detection of an adverse environmental condition to close the door.