Abstract: There is provided a detection system for detecting attempted entry onto the shaft-side roof of an elevator cab which includes a power supply for supplying power to the system, a proximity detector in electrical connection with the power supply which is disposed proximate the roof of the cab for detecting an object entering a zone of detection including the top of the cab, the detector in a preferred embodiment including an optical source for generating a detection beam and a corresponding optical receiver for receiving the detection beam when it is diffused by an object entering the detection zone and for providing a detection signal when the object enters the detection zone, and detection indicator responsive to the detection signal for indicating an attempted entry.