Well it IS Saturday!
Ten years ago or thereabouts, the BT main exchange for this part of the county lost power when an unrelated JCB cut the mains cable.
Standby generator/s wouldn't start and batteries began to run down. By the time a power source had been connected, peripheral exchanges had gone down and it was several more hours before everyone had a BT connection again.
999 was affected like everything else, but fortunately no major incidents occurred, and police cars had the job of touring the streets of a major city announcing that it was no use trying 999 for the present.