Hundreds of thousands of customers in the South are still without power over one week after Hurricane Helene made landfall.

More than 277,000 customers are in the dark in South Carolina and 230,000 are without power in North Carolina.

Another 200,000 are without power in Georgia.

"This has been a historic storm. We've never seen anything like this," Duke Energy spokesperson Bill Norton said. “The biggest challenge has been the unprecedented flooding. It’s not just poles and wires that are down -- it's the backbone of our system, the transmission infrastructure and substations."

Duke Energy has a "crew of 21,000 line workers, vegetation crews and more across the Carolinas," Norton said.

In North Carolina, crews have repaired more than 1.2 million power outages and are on track to restore an additional 27,000 customers by Friday night and another 69,000 in the hardest-hit areas by Sunday evening, Norton said on Friday.

The water line is almost to the top of the substation that serves Biltmore Village, North Carolina, and the substation will take three to four months to repair, Norton said.

Crews have wheeled in a 200,000-pound mobile substation to serve in the interim, Norton said, noting that it was a "slow, meticulous" process to get the mobile substation to the region because crews had to make sure the bridges hit by Helene could withstand it.

The mobile substation "will effectively allow us to bypass the substation for the next three to four months as we level it and build it again on higher ground," Norton said. "Those customers will have power even as we rebuild that substation."

The remnants of Hurricane Helene were not the only factor that contributed to the severity of the flooding that struck the mountain community of Asheville, North Carolina.

Several conditions in the region, including a precursor rain event and the topography of the land, gave rise to deadly flash flooding, experts told ABC News.

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The Federal Emergency Management Agency (FEMA) has launched a web page dedicated to pushing back on misinformation about the federal government's response to Hurricane Helene.

On the page, located on FEMA's website, FEMA tackles rumors like one claiming the agency doesn't have enough money for disasters, which the agency says it does.

Other rumors the agency debunks are claims FEMA is asking for cash and turning away volunteers. The agency says they'd never ask for money.

Another rumor getting attention on social media is that victims of Hurricane Helene only qualify for $750. FEMA debunks that rumor, saying people who apply for relief will get $750 for immediate needs. But the agency says people will qualify for more as their application moves through the agency.

-ABC News' Luke Barr

Vice presidential nominee Sen. JD Vance toured the damage caused by Hurricane Helene in Damascus, Virginia, with Republican Gov. Glenn Youngkin on Thursday.

"I think the biggest thing that I take away from this is: One, people need a lot of resources to rebuild, to rebuild the water system, to rebuild the roads, to put power back on, to restock people's refrigerators," Vance said. "But most importantly, I heard an unbelievable number of stories of incredible human tragedy, but also human heroism that saved a lot of lives and made it so that this very, very significant tragedy wasn't a whole lot worse."

When reporters asked Vance if he supported the call for Congress to go back into session and pass an emergency appropriations package to help those impacted by Helene, Vance said yes.

"Yes, ma'am, of course, we're going to support that," he said. "People, I think, need the help and certainly need the support."

-ABC News’ Hannah Demissie