HAZARD, Ky. — Firefighters and National Guard crews have swarmed into eastern Kentucky after days of deadly flooding, rescuing by the hundreds people who found themselves trapped in the perilous water.

Also preparing to send a delegation: the tiny community of Bremen, Ky., nearly 300 miles away. When Bremen was shredded last year by one of the worst tornadoes in state history, the mayor from a little town in the eastern part of the state came to help with the cleanup. That town, Hindman, was among the hardest hit in this week’s floods. So the mayor of Bremen immediately began planning trips across the state with trucks full of supplies — even as his own community continued to rebuild.

“I said, ‘You were here in December and helped us,’” Mayor Allen Miller of Bremen told the mayor of Hindman in a phone call. “‘Now it’s time for me to return the favor.’”

Officials have held up efforts like these as a testament to a kind of generosity ingrained in the culture of Kentucky, a spirit forged over generations of hardship in which communities had to rely on one another to pull through.

But that cycle of support is also a grave reminder of the turbulence wrought by natural disaster that has gripped the state in recent months and will make recovery from the latest calamity all the more difficult. Officials said on Saturday that at least 25 people had been killed in the floods (that figure was updated to 26 on Sunday morning), but it could take weeks for the full magnitude of the human toll and physical devastation to become clear.

“I wish I could tell you why we keep getting hit here in Kentucky,” Gov. Andy Beshear said during a briefing in which he updated residents on the rising death toll and displayed a sense of anguish and exhaustion that many in the state have felt after recurring disasters, including a powerful ice storm last year that cut off power to 150,000 people in eastern Kentucky, a flash flood last July that left many stranded in their homes and the rare December tornadoes that carved a nearly 200-mile path of destruction and killed 80 people.

“I wish I could tell you why areas where people may not have much continue to get hit and lose everything,” the governor went on. “I can’t give you the why, but I know what we do in response to it. And the answer is everything we can.”

These disasters — particularly the flooding and tornadoes — would be staggering setbacks for any community. But here, they have been especially calamitous, striking rural areas that were already deeply vulnerable after decades of decline.

“These places were not thriving before,” said Jason Bailey, the executive director of the Kentucky Center for Economic Policy, a nonpartisan think tank, noting the erosion of the coal industry and loss of manufacturing jobs. “To even get back to where they were is a long road.”

For communities inundated by the powerful floods, that road has only begun.

The worst of the devastation has been concentrated in roughly a half-dozen counties in the Appalachian region on the eastern edge of the state. At least 14 people, including four children, died in Knott County, officials said. More than 1,400 people have been rescued by boat and helicopter, and thousands remain without electricity.

Homes were pulled from their foundations. Bridges have washed out, leaving some remote communities inaccessible. “I’ve seen ditches formed where there weren’t ditches because of the rushing water,” said Dan Mosley, the judge-executive for Harlan County.

His community experienced only minor flooding, he said, so for the past several days, he has accompanied workers from the county Transportation Department with dump trucks equipped with snow plows to clear out roads blocked by muck and debris in neighboring communities. The worst destruction he saw was in Knott and Letcher Counti

“The pure catastrophic loss is hard to put into words,” he said. “I’ve just never seen anything like this in my career or even my life.”

In Breathitt County, at least four deaths had been confirmed, roughly a dozen people were missing and much of the county remained underwater. Many homes in the sparsely populated county were still inaccessible. The community was already struggling to find its footing after the last flood.

“We had another flood, a record flood, not 12 months ago, and a lot of families had just started getting their lives back on track,” said Hargis Epperson, the county coroner. “Now it’s happened all over again, worse this time. Everybody’s lost everything, twice.”

In Hazard, a city of just over 5,200 people in Perry County, 24 adults, five children and four dogs had taken shelter at First Presbyterian Church — a number that was almost certain to climb in the coming days. Their homes had been flooded or wiped out by a mudslide.

Some of them arrived soaking wet and caked in mud, said Tracy Counts, a Red Cross worker at the church. All she had to offer them was baby wipes; there was no running water.

“It’s making it a harder puzzle to solve, but we’re adapting and making it happen,” Ms. Counts said. “It’s just hard to ask for help when we’re all in the same boat.”

Melissa Hensley Powell, 48, was brought to the church after being rescued from her home in Hardshell, an unincorporated area of Breathitt County. She and her boyfriend had pulled her brother, who is paralyzed, out of their house and then carried out a mattress for him to lie on. They kept him dry by holding garbage bags and umbrellas over him.

Two days after her rescue, while having a lunch of Little Caesars pizza and bottled water, she said the gravity of what she had endured was soaking in. “It’s starting to,” she said. “We’re still in that adrenaline rush.”

At the church, one congregant has rented portable toilets. People have dropped off water, blankets and dog food, the donated items filling some of the pews.

“I know people have this image of Eastern Kentucky,” Ms. Counts said, acknowledging the painful perception among outsiders of the region as poor and backward. “But we are the first ones to step up. We are the first ones to ask, ‘How can we help?’”

But now, an onslaught of disasters was testing that spirit of support in profound ways.

It is difficult to link a single weather event to climate change, but the flooding and tornadoes have highlighted the vulnerabilities that Kentucky faces. For some, it has also underscored the failures to prepare, as experts warn of heavier rainfall, flash floods that are becoming shorter in span but more powerful in magnitude, and weather patterns overall becoming more erratic.

“Let’s be aware that this a new normal of incredibly catastrophic events, which are going to hit our most vulnerable communities,” said Alex Gibson, the executive director of Appalshop, the arts and education center in Whitesburg, Ky., comparing the litany of flooding disasters in eastern Kentucky with the devastation faced by poor island nations around the world in the era of climate change.

In the vast stretches of the state now contending with the aftermaths of flooding and tornadoes, Mr. Bailey said, the infrastructure had already been inadequate and the communities had been impoverished. “We have people who are living on the edge,” he said.

“So much of the wealth has been extracted,” he said. “In a topography that has been stripped, literally, of trees and mountainsides, flooding in particular becomes more likely, more risky, more dangerous — that’s what we’re seeing.”

And as much as the communities want to rely on one another to recover from the devastation, it would be difficult to summon the necessary resources on their own.

“The strain has been immense,” Judge Mosley, who is also an officer in the Kentucky Association of Counties, said of the widespread consequences from major disasters.

Without outside support, “this would be unsurvivable,” he said. “The federal government’s resources and our faith in God is the only thing that’s going to get us through this.”

Shawn Hubler contributed reporting.