State-run Unión Eléctrica reported a nationwide blackout around midday, the third major collapse in 2026 after outages in March. The crisis stems from an aging Soviet-era grid, poor maintenance, and severe fuel shortages after U.S. tariffs halted oil from Venezuela and Mexico, with only limited Russian supplies arriving. Cuban officials blame the U.S. embargo for an 'energy siege,' while critics point to decades of socialist mismanagement; partial power returned overnight to some areas, but full recovery may take days.