Elaborate control and monitoring structures have been developed for power-system operation. The basic operating structure is hierarchically organised from the main control centre, with the added provision of numerous automatic and protective devices to assist operators in effectively controlling the power grid. Centralised control has proved effective under normal conditions and for a range of disturbances for which the power system has been planned. However for disturbances of greater severity than allowed by planning criteria, this edifice does not avert the threat to the power system. By default, it is assumed that operators can control the consequences of these calamitous disturbances. Experiences throughout the world have shown the fallacy of this assumption. The threat of calamitous system disturbances has been mostly tackled from the aspect of a centralised control. As shown in this paper, a number of insuperable difficulties are created in adopting this approach. Instead, it is possible to utilise a method of distributed intelligence within the existing hierarchical control structure. This paper demonstrates not only the feasibility of this approach, but how it can monitor the system's dynamic reactions to control the after effects of the disturbances. This would allow developments enabling power systems to successfully withstand calamitous disturbances.