BAYAMÓN, Puerto Rico — Power was restored to nearly all electrical customers across Puerto Rico on Wednesday after a sweeping blackout plunged the U.S. territory into darkness on New Year’s Eve.

By Wednesday afternoon, power was back up for 98% of Puerto Rico’s 1.47 million utility customers, said Luma Energy, the private company overseeing transmission and distribution of power in the archipelago. Lights returned to households as well as to Puerto Rico’s hospitals, water plants and sewage facilities after the massive outage that exposed the persistent electricity problems plaguing the island.

Still, the company warned that customers could still see temporary outages in the coming days.

“Given the fragile nature of the grid, we will need to manage available generation to customer demand, which will likely require rotating temporary outages,” Juan Saca, president of Luma Energy, said in a statement.

The lights went off in Puerto Rico at 5:30 a.m. on Tuesday, darkening almost the entire archipelago.

— The Associated Press