Most of Puerto Rico hit by New Year’s Eve power outage

San Juan, Puerto Rico — A massive power outage hit nearly all of Puerto Rico early on New Year’s Eve, leaving more than 1.2 million of the U.S. territory’s 1.47 million clients without electricity, according to Luma Energy, a private company that oversees electricity transmission and distribution on the island. By late Tuesday evening, Luma said power had been restored to about 700,000 clients, roughly half of those affected.

The company had warned early Tuesday that it could take up to 48 hours to restore electricity across the island, “conditions permitting,” but a couple hours later it said service had been restored to in some areas.

Luma said late Tuesday that at least 31 hospitals and medical centers across Puerto Rico were up and running again, along with both of capital city San Juan’s airports.

Luma Energy spokesperson Hugo Sorrentini told CBS News the blackout was caused by a failure in one of the electric lines at one of the main power plants, called Costa Sur. The failure in the line caused the power plant to go out of service and then “created a waterfall effect in the system,” he said, which led to the other power plants on the island going out of service.

A full investigation into what caused the electric line to fail was underway, Sorrentini said. 

Reuters quoted Ivan Baez, a spokesperson for Puerto Rico’s primary energy generator Genera, as saying the failure of the grid was believed to have been caused by a problem with a line operated by Luma, but that it had also brought down plants belonging to Genera and some other private electricity generators.

Puerto Rico Gov. Pedro Pierluisi said in a post on social media that his administration was communicating with both Luma and Genera “regarding the massive blackout affecting a large part of the Island due to a critical fault.”

He said work was underway to restore electrical supply and that the government was “demanding answers and solutions from both Luma and Genera, who must expedite the restart of the generating units outside the fault area and keep the people duly informed about the measures they are taking to restore service throughout the Island.”

Puerto Rico continues to struggle with chronic power outages blamed on a crumbling power grid that was razed by Hurricane Maria, a powerful category 4 storm that struck the island in September 2017. The system was already in decline prior to the storm given years of lack of maintenance and investment.

In a message posted Tuesday on social media, former New York Gov. Andrew Cuomo, whose state has one of the biggest populations of Puerto Ricans in the continental U.S., said residents of the territory had been “treated as second class citizens for far too long.”

“The fact that, as Americans, they don’t have a reliable electric grid and suffer sporadic blackouts on a continuous basis is indefensible and would not be tolerated anywhere else in the United States,” said Cuomo. “The federal government must finally acknowledge its responsibility to Puerto Rico and provide the resources and expertise necessary to end this cycle of insanity once and for all.”

contributed to this report.