Puerto Rico experienced a massive power outage beginning around 5:30 a.m. local time Tuesday morning, leaving more than 80% of the island without electricity on New Year's Eve. "While the cause of the outage is under investigation, preliminary findings point to a failure in an underground line," Luma said in a statement to Reuters.

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.

Power was restored for some customers since the blackout started at 5:30 a.m., but LUMA Energy said the full restoration process could take one to two days.