Entrance security system

An entrance denial security system comprises an entrance barrier closing an entrance into a secured area having a plurality of structural tubular elements with hollow cores forming a rigid integral barrier. At least one optical fiber sensor line is laced through the hollow cores of the structural elements for detecting a fault condition signifying an unauthorized intrusion attempt. A processor in communication with the fiber sensor line generates a fault signal in response to the occurrence of a fault condition and identifying the entrance where the fault condition occurred. A communication device operatively associated with the processor communicates the fault signal and an alarm so that a proper security response can be made to the fault condition. The system further comprises a plurality of intrusion sensors disposed at certain locations. Preferably primary and secondary optical fiber sensor lines are routed through the structural elements and intrusion sensors, and primary and secondary scanning units pulse signals along the sensor lines and receive reflected signals back from the sensor lines. In the event of a cut through in the sensor lines, the primary sensor line monitors the barrier and sensors downstream of the break, and the secondary sensor line is activated to monitor the barriers and sensors downstream of the break.