Two-stage, sequential operation protective assemblies are provided, including a primary protective device (20) having an element (32) which shifts in response to operation thereof (preferably a rupturable burst member (35)), together with a secondary protective device (22). An actuating assembly (24) interconnects the primary and secondary protective devices (20, 22) and has an actuating cable assembly (28) preferably including a cable (94) and a frangible component (86). In certain embodiments, an operator (28) for the secondary device (22) may be provided which includes an actuator (106) carried by the cable (94). Upon operation of the primary protective device (20), the cable (94) and frangible component (86) are tensioned and translated in a first direction. The component (86) then severs, which causes operation of the secondary protective device (22).