A fallen high-voltage cable triggered a power outage that cut electricity to large parts of the Czech Republic on Friday, darkening swathes of Prague and five northern and eastern regions from around noon local time. Grid operator CEPS said the failure on the 400-kV V411 transmission link forced eight substations offline and split the network into isolated “islands”, leaving about 500,000 customers without supply at the height of the blackout. The disruption halted metro, tram and rail services in the capital, stopped trains on at least five lines nationwide and temporarily idled factories, including Orlen Unipetrol’s Litvinov petrochemical complex. Firefighters reported 215 incidents of people trapped in elevators, while roughly 1,000 mobile phone base stations switched to back-up power. CEPS declared a state of emergency but restored electricity to all transmission substations within an hour and to most households and businesses by 1600 GMT, when fewer than 2,000 customers were still offline. Prime Minister Petr Fiala called the situation “extraordinary and unpleasant”, adding that preliminary checks showed no sign of a cyber-attack or problems with renewable generation. Authorities have opened an investigation into why the fallen conductor caused such a widespread cascade in a system that is scheduled for reinforcement by 2028.