Cuba has suffered a massive power outage affecting Havana and the country’s provinces that has left millions in the dark.

Cuba’s power grid collapsed Friday night, triggering a nationwide power outage and plunging its more than 10 million people into darkness.

Cuba has struggled with blackouts in recent months, including a nationwide one in December. Friday’s power failure was the fourth widespread one in five months. Government officials blame U.S. economic sanctions for the ongoing crisis, while others point to aging infrastructure, fuel shortages and the island’s susceptibility to hurricanes.