Abstract: A new and improved overhead door safety apparatus is disclosed for a cable controlled door whose movement is guided by a stationary guide track. The new apparatus includes a brake assembly which is attached to the door and which is responsive to a decrease in a predetermined cable tension. When the decrease in the predetermined cable tension takes place, the overhead door safety apparatus is actuated causing the brake assembly to apply a braking action on movement of the overhead door. More specifically, in the brake assembly, a cable-tension-responsive track follower guides motion of the door by following the track. The cable-tension-responsive track follower has a first and a second operating state. The first operating state permits smooth movement of the cable-tension-responsive track follower along the track as the door moves when a control cable maintains a predetermined amount of cable tension.