KERRVILLE, Texas — Crews picked through mountains of debris and waded into swollen rivers Monday in the search for victims of catastrophic flooding that killed nearly 90 people over the July Fourth weekend in Texas, including more than two dozen campers and counselors from an all-girls Christian camp.

With additional rain on the way, more flooding still threatened in saturated parts of central Texas. Authorities said the death toll was sure to rise as crews looked for many people who were missing.

Operators of Camp Mystic, a century-old summer camp in the Texas Hill Country, said they lost 27 campers and counselors, confirming their worst fears after a wall of water slammed into cabins built along the edge of the Guadalupe River.

“We have been in communication with local and state authorities who are tirelessly deploying extensive resources to search for our missing girls,” the camp said in a statement. Authorities later said that 10 girls and a counselor from the camp remain missing.

The raging flash floods — among the nation’s worst in decades — slammed into riverside camps and homes before daybreak Friday, pulling sleeping people out of their cabins, tents and trailers and dragging them for miles past floating tree trunks and automobiles. Some survivors were found clinging to trees.

Piles of twisted trees sprinkled with mattresses, refrigerators, coolers and canoes now litter the riverbanks. Search-and-rescue teams used heavy equipment near Kerrville to remove large branches while volunteers covered in mud sorted through chunks of debris, piece by piece.

In the Hill Country area, home to Camp Mystic and several other camps, searchers have found the bodies of 75 people, including 27 children, Kerr County Sheriff Larry Leitha said.

Fourteen other deaths were reported in Travis, Burnet, Kendall, Tom Green and Williamson counties.

Gov. Greg Abbott said Sunday that 41 people were unaccounted for across the state and more could be missing.

Authorities vowed that one of the next steps will be investigating whether enough warnings were issued and why some camps did not evacuate or move to higher ground in areas long vulnerable to flooding.

On Thursday the National Weather Service advised of potential flooding and then sent out a series of flash flood warnings in the early hours of Friday before issuing flash flood emergencies — a rare step that alerts the public to imminent danger.

Authorities and elected officials have said they did not expect such an intense downpour, the equivalent of months of rain.

Kerrville City Manager Dalton Rice said one of the challenges is that many camps are in places with poor cellphone service.

President Donald Trump signed a major disaster declaration Sunday for Kerr County and said he would likely visit Friday. He said it wasn’t the time to talk about whether he was still planning to phase out the Federal Emergency Management Agency and added that he doesn’t plan to rehire any of the federal meteorologists who were fired this year as part of widespread government spending cuts.

“This was a thing that happened in seconds. Nobody expected it,” the president said.

The NWS office responsible for that region had five staffers on duty as thunderstorms formed over Texas on Thursday evening, the usual number for an overnight shift when severe weather is expected. Current and former NWS officials defended the agency, pointing to urgent flash flood warnings issued in the pre-dawn hours before the river rose.

“This was an exceptional service to come out first with the catastrophic flash flood warning and this shows the awareness of the meteorologists on shift at the NWS office,” said Brian LaMarre, who retired at the end of April as the meteorologist-in-charge of the NWS forecast office in Tampa, Florida. “There is always the challenge of pinpointing extreme values, however, the fact the catastrophic warning was issued first showed the level of urgency.”

Questions remain, however, about the level of coordination and communication between NWS and local officials on the night of the disaster. The Trump administration has cut hundreds of jobs at NWS, with staffing down by at least 20% at nearly half of the 122 NWS field offices nationally and at least a half-dozen no longer staffed 24 hours a day. Hundreds more experienced forecasters and senior managers were encouraged to retire early.

Democrats on Monday pressed the Trump administration for details about the cuts. Senate Minority Leader Chuck Schumer demanded that the administration conduct an inquiry into whether staffing shortages contributed to “the catastrophic loss of life.”

Former federal officials and experts have said Trump’s indiscriminate job reductions at NWS and other weather-related agencies will result in brain drain that imperils the federal government’s ability to issue timely and accurate forecasts.

“This situation is getting to the point where something could break,” said Louis Uccellini, a meteorologist who served as NWS director under three presidents, including during Trump’s first term. “The people are being tired out, working through the night and then being there during the day because the next shift is short staffed. Anything like that could create a situation in which important elements of forecasts and warnings are missed.”