Power outages are a frustratingly frequent occurrence for many Puerto Ricans. A string of blackouts during the summer prompted protests and a state of emergency.

A blackout hit nearly all of Puerto Rico early on Tuesday as the U.S. territory prepared to celebrate New Year’s, leaving more than 1.3 million clients in the dark. Officials said it could take up to two days to restore power.

A “massive blackout” that hit much of Puerto Rico early Tuesday may keep the U.S. territory in the dark through New Year’s Eve and beyond, according to the governor and the private energy company that provides power to the island.