Crews restore power to nearly all customers after island-wide blackout hit Puerto Rico

More than 1.45 million customers had electricity less than 48 hours after the outage hit, according to Luma Energy, which oversees the transmission and distribution of power on the island.

Luma warned that "some customers may continue to experience temporary outages due to limited generation."

"Obviously, Luma still has work to do," she said. "It is a shame for our people ... that we have such an insufficient, mediocre system."

Normally, a couple thousand customers are temporarily without power every week in Puerto Rico for various reasons.

González noted that more than 98% of customers also had water.

"We have overcome, thank God, a great crisis this week," she said.

It wasn't immediately clear what caused the failure, although authorities are investigating whether a series of breakers failed or if overgrown vegetation is to blame.

González said she expected to receive a preliminary report in upcoming days.

It's the second massive blackout to hit Puerto Rico in less than four months. The previous one happened on New Year's Eve.