Residents of Pasco County, Florida, just north of Tampa, are facing "a level of devastation in our county that, quite honestly, I haven't seen in the 20-plus years that I've lived here," county administrator Mike Carballa said.

Pasco County’s emergency center received about 400 to 500 calls for service early Friday morning after landfall, Carballa said. Of those calls, crews were only able to answer about 20%, he said.

There were fires that first responders saw but could not initially reach, which Carballa called "heart wrenching."

"We felt very, very helpless," he said.

Despite Helene's devastation, officials said they saw residents helping their neighbors, like by taking them to safety in boats.

The initial response phase has ended and officials are now moving into damage assessment, Carballa said.

-ABC News’ Victoria Arancio

The storm surge, wind damage and inland flooding from Hurricane Helene was catastrophic.

Friday’s flooding in western North Carolina surpassed records that stood for more than a century. The French Broad River in Asheville, North Carolina, peaked at 24.67 feet, breaking the previous record of 23.1 feet from 1916.

More than 2 dozen river gauges are in major flood stage due to this historic rainfall. Many of these rivers will take several days to return to normal after reaching record-high levels on Friday.

On Saturday, parts of North Carolina, Tennessee and Virginia remain under flash flood emergencies.

Helene, now a post-tropical cyclone, is stalling over the Tennessee Valley, bringing more rain and scattered gusty winds through the weekend.

-ABC News’ Daniel Amarante

A public health emergency was declared in Georgia on Friday, U.S. Department of Health and Human Services Secretary Xavier Becerra said.

"We will do all we can to assist Georgia officials respond to the health impacts of Hurricane Helene," Becerra said. "We are working closely with state and local health authorities, as well as our partners across the federal government, and stand ready to provide additional public health and medical support."

Administration for Strategic Preparedness and Response "has deployed teams to assist in a rapid combined federal and multi-state response to Hurricane Helene," said Assistant Secretary Dawn O’Connell. “We are on the ground and ready to support local health requests."

The HHS had declared an emergency for Florida on Thursday.

Helene is now post-tropical and is no longer a depression, but its remnants continue to produce dangerous weather over portions of the southern Appalachians and Tennessee Valley, the National Weather Service said.

Flash flood emergencies remain in effect for western North Carolina and portions of Tennessee and Virginia.

A tornado watch remains in effect from eastern North Carolina to Virginia Beach back to Roanoke, Virginia. Several tornadoes have been reported on Friday.

The center of Helene is now over Kentucky with heavy rain and gusty winds across a large area from Missouri to Ohio to the Carolinas. Flash flooding and strong winds will continue through Friday night.

-ABC News' Melissa Griffin