Cuba suffered a massive power outage Friday night affecting Havana and the country's provinces that 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. “At around 8:15 p.m. tonight, a failure at the Diezmero substation caused a significant loss of generation in the west of #Cuba and with it the failure of the National Electric System,

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.