BUCKHORN, Ky. – Devastated communities across eastern Kentucky began digging out in earnest Sunday as the state's death toll rose to 26 and another round of storms threatened to expand the historic flooding.

Dozens of people remained unaccounted for, and some areas remained inaccessible to search and rescue teams. Spotty cellphone service added to the chaos.

Still, signs of survival and heroism were everywhere, Gov. Andy Beshear said.

“Many people that have lost everything, but they’re not even getting goods for themselves, they’re getting them for other people in their neighborhoods, making sure that their neighbors are OK,” Beshear said.

Excessive runoff from showers and thunderstorms Sunday and Monday could result in additional flooding of rivers, creeks and streams across much of central and eastern Kentucky, the National Weather Service warned. Rainfall rates of up to 2 inches an hour could spark flash flooding, especially in areas that see repeated rounds of thunderstorms.

Hard-hit counties including Floyd, Knott and Perry are among the areas under alert. Power, water, shelter and cell service are major issues in some communities, Beshear said. The flooding overwhelmed some neighborhoods where people didn’t have much to begin with, he said, and a heat wave forecast this week will further deepen the suffering.

The flooding has caused hundreds of millions of dollars of damage and displaced  hundreds of people, he said.

"We want to make sure that we wrap our arms around our Eastern Kentucky brothers and sisters and make sure that they are ok," Beshear said. "We will be there for you today, tomorrow next week, next year. We are not going anywhere. We are going to help you rebuild."

Beshear asked that people donate cleaning supplies or water or donate directly to the state flood relief fund, where 100% of donations go to Kentuckians affected.

►Bigger picture: Climate change exposes growing gap between weather we've planned for – and what's coming

►In Eastern Kentucky: Flooding brings up memories of previous disasters

►Where is the flooding? See photos, drone videos of the devastation

The hardest hit areas of eastern Kentucky received almost a foot of rain late last week. The North Fork of the Kentucky River reached 20.9 feet in Whitesburg, more than 6 feet over the previous record, and crested at a record 43.5 feet in Jackson, National Weather Service meteorologist Brandon Bonds said.

The rains of Sunday and Monday won't be the end of it, the weather service warned. Thunderstorms are also possible on Tuesday, as well as Thursday through Saturday.

The dozen shelters opened for flood victims across the state drew 388 occupants Sunday, FEMA said. About 70 trailers – purchased by the state for use during deadly tornadoes that ripped through Western Kentucky in December – are being deployed as temporary shelters.

"Yesterday our first travel trailers arrived and we are working fast to establish additional shelter options," Beshear said.

The state also plans to work with area hotels to pay room costs for displaced residents – and to cover funeral expenses for people killed in the floods.

More than 1,200 rescues have taken place. Still, multiple state police posts have been getting calls from people unable to contact family and friends. The National Guard has been called out and is helping first responders going door to door to find as many people as possible, he said. But the heavy rains are making it difficult, and some people cannot be reached, he said.

Damage to critical infrastructure is also providing challenges to rescuers. Scores of bridges are out and roads washed away, making it hard to access some communities to deliver desperately needed water and other necessities he said.

"The next couple days are going to be hard," Beshear said. "We've got rain, and maybe even a lot of rain that is going to hit the same areas."

Among the stories of survival emerging from the wreckage is a 17-year-old girl whose home in Whitesburg was flooded Thursday. Chloe Adams put her dog, Sandy, in a plastic container and swam 70 yards to safety on a neighbor’s roof, waiting for hours until daylight before a relative in a kayak arrived and removed them from harm's way

“She is a hero. I love you Chloe. You are simply amazing," her father Terry wrote on Facebook in a post that included a photo of his daughter sitting atop barely above the floodwaters, clinging to the dog. “We lost everything today … everything except what matters most.”

In southeastern Kentucky, some small mountain towns that were initially difficult to reach because of roads blocked by fallen trees or high water were beginning to dig out Sunday. In Buckhorn, a Perry County hamlet of about 130 people, a branch of the Middle Fork of the Kentucky River carried away cars and destroyed some homes during Wednesday and Thursday’s historic floods.

One of its critical community gathering points was also decimated: the Buckhorn School, which dates to the early 1900s and whose more than 300 students are drawn from across the mountainous region.

Torrents of water and debris that rose from Squabble Creek, which runs alongside the school, smashed walls, broke windows and tore the parking lot asphalt into pieces just two weeks before the school year was to begin.

Like other schools in the region, the county K-12 Buckhorn public school serves as an important hub of resources for students whose families live on low incomes, said special education teacher Kristie Combs, 46.

“It’s more than just a school, it’s a community,” said Combs, who surveyed the damage for the first time Saturday after water receded from a road leading to her home in a town 20 miles away. 

In a nearby neighborhood along the creek, where generators hummed on Saturday, Teresa Engle, 33, said her two kids, Haley, 8, and EJ, 6, would likely attend in another school or county. 

For now, Engle said she was just happy to be alive. In the early hours of Thursday, she said her family was trapped by the roaring waters that reached the door but left it intact. Others were less fortunate.

“We could just see cars and houses going by,” she said. “I’ve never been so terrified.”

On Saturday, her daughter gave away a stuffed animal and a pair of boots to a neighbor’s child whose home had been destroyed.

Buckhorn School teachers and students were handing food, water and supplies to families in need.

“Some kids had homes washed away,” said high school teacher Jalen Cooper, 27, explaining that some were staying in hotels and others were packing in relatives who have generators.

“It’s going to take a long time, a lot of effort and a lot of grit,” he said. “But we know how to push through.”

Knott County had the highest death toll at 14, according to the local coroner, and four young siblings were among the dead. Residents along Troublesome Creek in the quiet community of Fisty call a short stretch of Kentucky Route 550 "Rainbow Lane." Each house is painted a different color, but the homes have been reduced to mangled heaps of cinder blocks and destroyed possessions. Some residents retreated to the fire department building at a higher elevation as the raging creek caused unprecedented destruction.

"It never got like this before," Bert Combs, 58, said as he stood shirtless, peering at the creek and what was left of Rainbow Lane. The rain, he said, "just kept coming."

The state must "build back stronger" to compensate for the more intense storms driven by the changing climate, Beshear said. Roads, bridges, culverts, water and wastewater systems and flood walls must be designed to withstand greater intensity, he said.

An infrastructure bill drawing bipartisan support is a good start, Beshear said.

"The infrastructure is so expensive," he told NBC's "Meet the Press." "If we truly want to be more resilient, it is going to take a major federal investment, as well as here in the state. We're ready to do our part."

The Biden administration has added individual assistance to his Major Disaster Declaration to help the people of eastern Kentucky who "have lost everything," noting recovery will be long-term.

"I’m taking more action to help the families being displaced and lives lost," President Joe Biden said in a statement.

FEMA said the individual assistance can include grants for temporary housing and home repairs, low-cost loans to cover uninsured property losses, and other programs to help individuals and business owners recover from the effects of the disaster.

Contributing: Lucas Aulbach, Louisville Courier Journal; The Associated Press

Bacon reported from Arlington, Virginia.