San Juan, Puerto Rico — A major power outage hit nearly all of Puerto Rico early Tuesday as the U.S. territory prepared to celebrate the New Year. More than 1.2 million of the 1.47 million customers were without power, according to Luma Energy, the private company that oversees the island’s electricity transmission and distribution.

It was not immediately clear what caused the widespread power outage or when power would be restored. Luma officials did not immediately return a message for comment.

In a post on X, Luma said he was in contact with crews and companies monitoring power generation in Puerto Rico to resolve the outage. It said it would offer details as soon as possible.

A spokesman for Genera PR, which oversees power generation, was not immediately available for comment.

Puerto Rico Governor Pedro Pierluisi said ua publish on social networks that his management communicated with both LUMA and Gener “in connection with a major power outage that affected a large part of the island due to a critical failure.”

He said work was underway to restore electricity supply and that the government “requires answers and solutions from both LUMA and Genera, which must speed up the restart of generating units outside the fault area and inform people in a timely manner of the measures they are taking to restore service on the whole island.”

However, speaking to the Telemundo network late Monday, Josué Colón, head of the Puerto Rican Electricity Authority, said it could take a few days to fully restore the service.

Puerto Rico continues to struggle with chronic power outages blamed on the crumbling power grid that was leveled by Hurricane Mariaa powerful Category 4 storm that hit the island in September 2017. The system was already in decline before the storm due to years of lack of maintenance and investment.