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

Millions of people in Cuba remained without power Saturday after a failure of the nation’s electric grid left the island in the dark the previous night. The massive blackout is the fourth in the last six months as a severe economic crisis plagues the Caribbean country.

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.