SAN JUAN, Puerto Rico (AP) — A blackout hit nearly all of Puerto Rico early 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.

Nearly half of the island’s 1.4 million utility customers had power by late Tuesday night. The electricity provider said it would take up to 48 hours to fully restore service.

Puerto Rico experienced a massive power outage beginning at about 5:30 a.m. local time Tuesday morning. "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.

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 major power outage plunged much of Puerto Rico into darkness on New Year's Eve, with the US island territory's electric utility saying restoration could take up to two days.

Most Puerto Ricans woke up on New Year’s Eve to widespread electricity blackouts, the latest consequence of a crumbling power grid that was destroyed by Hurricane María in 2017 and never fully restored by the private companies that took it over.

More than 1 million Puerto Ricans are without power on New Year’s Eve as a blackout hit nearly all of the island early Tuesday morning. Nearly 90 percent of 1.47 million clients across Puerto Rico

Jenniffer González Colón was sworn in Thursday as Puerto Rico’s new governor as the island prepared for a normally ebullient ceremony overshadowed by widespread anger over a blackout that hit the U.S.

Puerto Rico's power is restored after a New Year's Eve blackout, but grid issues persist. Straight Arrow News Straight Arrow News

Most of Puerto Rico's power was restored since the New Year's Eve blackout that left a majority of the island in the dark. Around 99% if the island now has energy once again, according to Luma Energy,