At least 80 dead in Texas following heavy rains and 'catastrophic flooding,' say officials

At least 80 people are dead and many more are missing in Texas in the wake of torrential rains and resulting flooding.

By far the greatest number of fatalities occurred in Kerr County, where 68 people are believed to be dead, according to officials, including 28 children.

In Travis County, six people are believed dead, with three dead in Burnet County, two dead in Williamson County and one dead in Tom Green County, officials said in an update Sunday evening.

Abbott said that 41 people remained unaccounted for.

Heavy rain that pounded Kerr County, Texas, on Friday, led to "catastrophic" flooding, Kerr County Sheriff Larry Leitha said at a news conference Sunday morning.

There are several major camps in the area. At one of them, Camp Mystic, on the banks of the Guadalupe River, at least 11 of its 750 young female campers and one counselor remained unaccounted for on Sunday, Leitha said.

Leitha said that more than 400 first responders from at least 20 agencies are helping in the search for victims.

"We will continue our search efforts until everybody is found," Leitha said.

Camp Mystic said in a letter to parents, "If your daughter is not accounted for, you have been notified. If you have not been personally contacted, then your daughter is accounted for."

President Donald Trump posted on his Truth Social platform on Sunday that he had signed what he called a "major disaster declaration" for Kerr County.

"These families are enduring an unimaginable tragedy, with many lives lost, and many still missing. The Trump Administration continues to work closely with State and Local Leaders," Trump wrote.

After Trump signed the disaster declaration requested by Texas Gov. Greg Abbott, Department of Homeland Security Secretary Kristi Noem, who was on the ground in Texas, said the Federal Emergency Management Agency (FEMA) will partner with Texas state and local authorities "to ensure the people of Texas get the support they need as search efforts continue and recovery begins."

Up to 12 inches of rain has already fallen in Kerr County, about 60 miles north of San Antonio, with the rain ongoing through the evening.

Dozens of people were rescued Friday morning, and search efforts are ongoing Sunday, Kerr County officials said.

"This came at night when people were asleep in bed," Kerrville Mayor Joe Herring said at an earlier news conference, overcome with emotion. "Please pray for our community."

The Guadalupe River in Kerr County rose a whopping 26 feet in 45 minutes, Patrick said. The river reached its second-highest height on record, surpassing a 1987 flood level, the National Weather Service said.

While most residents should avoid traveling, "those near creeks, streams, and the Guadalupe River should immediately move to higher ground," the sheriff's office warned.

At one campground along the Guadalupe River, people filmed videos of themselves evacuating when they noticed flood water encroaching under their vehicle. Other videos showed cars and cabins submerged.

"I was up all night keeping an eye on weather alerts. 2 a.m. there was a river flood warning. The river was a good distance from our site, so we thought we would be fine," one camper, Katie, told ABC News via Instagram. "At about 5:30 a.m., we heard banging on our RV door, yelling for us to get out now. The Guadalupe River had risen rapidly. We got the kids in the truck and were prepared to leave our camper behind if need be. We were able to hook up our camper and get it out too."

"The river was up to the back of our campsite when we left. The river was raging and you could hear trees and objects breaking," she said. "It was a very scary situation, but we are very blessed by the workers at the park for waking people up and getting us out of there. Praying for everyone affected by the flooding."

ABC News' Mireya Villarreal, Kenton Gewecke and Helena Skinner contributed to this report.