The blackout began when a transmission line at a substation in Havana shorted, triggering a chain reaction that caused the entire island's power generation to shut down. This incident marked the fourth nationwide blackout since October.

Experts have attributed recent blackouts in Cuba primarily to fuel shortages, aging infrastructure and economic sanctions. Outside of Havana, many Cubans have experienced rolling blackouts for weeks.Millions of people in Cuba remained without power for a second night in a row on Saturday as the island nation dealt with a major power outage.

Cuba's capital, Havana, partially restored electricity after a statewide grid collapse left 10 million without power. This is the fourth nationwide blackout since October, exacerbated by outdated oil-fired plants and reduced oil imports.