Around a third of Puerto Rico's population remains in the dark amid a series of earthquakes. The island's power authority said 600,000 customers have power, but around 900,000 people still don't know when the lights will return.

The power plant in Guayanilla that generates more than a quarter of the island's power has been severely damaged, and there's disagreement about when it will be back up and running.

"You can see that most of the structure is compromised," Angel Perez, the operations manager at the Costa Sur Power Plant, told CBS News correspondent David Begnaud.

Tanks used to clean water, the first step in the energy generation process, were knocked over inside the plant. Without those tanks, "we cannot even think to provide power to anybody," Perez said.

From those tanks, the water would be sent to even larger tanks outside the plant, which Perez said have also been damaged.

"There is a fracture in the middle, in the base of the tank," he said.

There also was damage to a control room and a turbine. And with Costa Sur not generating any energy, hundreds of thousands of people could go without power.

"What's the reality? Do you think people are going to have to sort of get used to having power maybe half the day and not having it the other half?" Begnaud asked Perez.

"We are going to work 24 hours around the clock," Perez said.

Pressed to be as realistic as possible, Perez said, "No less than a month."

But Jose Ortiz, the CEO of the Puerto Rico Electric Power Authority, said the plant "will be out for probably over a year."

"How much of this is earthquake-related or how much is it just old equipment that hasn't been cared for and updated?" Begnaud asked.

"It's both really. To be honest, those plants have over 60 years basically," Ortiz said. "Imagine you have a taxi, 60 years old, and you are required to run that 24/7. That's the kind of business we're running."



When people in Puerto Rico heard Ortiz say it could take a year before the plant was running again, there was a trending hashtag on Twitter calling for him to resign.

Ortiz said he's asking FEMA to supply a special generator that would provide 500 megawatts of electricity, which is more than half of what this entire plant can provide. But as of right now, the emergency declaration President Donald Trump signed doesn't allow FEMA to provide the generators that are needed here.