Most people in Puerto Rico woke up Thursday with no electricity after a blackout hit the entire US island territory in the Caribbean.
The Luma electric company said the outage Wednesday evening may have been caused by a failed circuit breaker at a power plant. It said the precise cause was not yet known.
The specialized website poweroutage.us said that as of 0320 GMT Thursday, all 3.2 million residents of the island were without electricity.
"Given the massive size and scope of the outage, power restoration could extend well into Thursday and Friday for some areas," Luna said.
Puerto Rico has suffered from major infrastructure problems for years. Its electrical grid was privatized in June 2021 in an effort to resolve the problem of persistent blackouts.
But that same month a fire at a transformer triggered yet another outage.
Thousands of fed up residents marched in protest in October.
The former Spanish colony became a US territory in the late 19th century before gaining the status of associated free state in 1950.
After years of financial woes and recession, in 2017 the island declared the largest bankruptcy ever by a local US administration.
That same year Puerto Rico was hit by hurricanes Irma and Maria, which devastated the island, including its electrical grid, worsening the economic crisis.
As if a symbol of the island's crumbling infrastructure, in 2020 the celebrated Arecibo Observatory telescope, which once starred in a James Bond film, collapsed when its 900-ton receiver platform plunged 450 feet (140 meters) onto the radio dish below. It had been in service for 57 years.