(NewsNation) — At least 25 people died — including four children — in flash flooding across Kentucky, the state’s governor said Saturday.

Among those who died were four children from the same family, the Knott County coroner said. Gov. Andy Beshear said the number would likely rise significantly and it could take weeks to find all the victims.

More than 330 people have sought shelter, and there has been extensive property damage in the state.

Beshear flew over parts of the flood-stricken region on Friday and described it as “just total devastation, the likes of which we have never seen.”

“We are committed to a full rebuilding effort to get these folks back on their feet,” Beshear said. “But for now, we’re just praying that we don’t lose anybody else.”

The rain let up early Friday after parts of eastern Kentucky received between 8 and 10 1/2 inches over 48 hours. Some waterways were not expected to crest until sometime Saturday.

“From everything we’ve seen, we may be updating the count of how many we lost for the next several weeks,” Beshear said. “In some of these areas, it’s hard to know exactly how many people were there.”

The governor predicted it would take a least a year for the state to fully rebuild.

Austin and Brianna Imhoff lost everything in the flooding. They told Nexstar’s NewsNation they were still trying to process what had happened.

“You don’t really know what happened unless you’re living in it,” Austin said. “Unless you’re there and the water is rising a foot every five minutes, you don’t understand it.”

President Joe Biden on Friday approved a major disaster declaration for the Commonwealth of Kentucky and ordered federal aid to supplement commonwealth and local recovery efforts in 13 counties.

Perry County is one of the hardest-hit areas of the state. Almost everyone in the area suffered some sort of damage. Perry County Sheriff Joe Engle said his 82-year-old great aunt drowned in the flood waters.

“We’ve still got a lot of searching to do,” said Jerry Stacy, the county’s emergency management director.

Nonprofit groups like the “Cajun Navy” have stepped up to help with search and rescue efforts and are still asking for more volunteers to join their efforts, said Cajun Navy ground force founder Rob Gaudet.

He said “the clock is ticking” for people to save their homes.

“Communication systems are down, there’s a lot of danger,” Gaudet said. “The longer these homes sit, the harder it will be to repair them. Mold will set in… there’s enormous challenges to a flood.”

Intense downpours have happened across rural Appalachia, with steep hills and terrain of narrow river channels funneling water into Kentucky, Virginia and West Virginia. Water tumbled down hillsides and into valleys and hollows where it swelled creeks and storms coursing through small towns. The torrent engulfed homes and businesses and trashed vehicles. Some people were marooned on steep slopes by mudslides.

St. Louis, Missouri has also seen a lot of rainfall, which has made it challenging for the paved city environment to soak it all up.

Scientists warn climate change is to blame for making these kinds of weather disasters more common.

“It’s a battle of extremes going on right now in the United States,” said University of Oklahoma meteorologist Jason Furtado. “These are things we expect to happen because of climate change. … A warmer atmosphere holds more water vapor and that means you can produce increased heavy rainfall.”

The Associated Press contributed to this report.