“We have experienced a massive power outage across the island due to the unexpected shutdown of all power generation plants,” Genera PR, a private company that operates those plants, said in a statement carried on X.

Luma Energy, which distributes electricity, said more than 1.1 million customers were without service as of 2025.

It said it was working to identify the cause of the problem and “safely restore service.”

A power outage plunged most of Puerto Rico into darkness last New Year’s Eve.

Such incidents have become commonplace since Hurricane Maria tore across the Spanish-speaking territory in 2017, exacerbating existing power grid issues.

The latest blackout was caused by a “transmission line failure between the Cambalache power plant and the municipality of Manati,” the island’s government said in a statement late on Wednesday night.

The Puerto Rico federal affairs administration said it expected the grid to “continue recovering gradually throughout the night,” with more than 266 megawatts of electricity generation already restored.