Hunt, Texas - Rescuers in Texas on Monday searched for bodies swept away by flash floods that killed more than 80 people, including 27 girls and counselors at a summer camp.

The nation was shocked at the disaster over the Fourth of July holiday weekend, and forecasters warned that thunderstorms threatened more flooding over saturated ground.

"Camp Mystic is grieving the loss of 27 campers and counselors following the catastrophic flooding," the camp said in a statement.

"Our hearts are broken alongside our families that are enduring this unimaginable tragedy."

Texas Texas floods: Desperate search for missing continues amid climbing death toll

President Donald Trump said he may visit Texas later this week, but brushed off concerns his cuts to weather forecasting and related federal agencies had weakened warning systems.

Instead, he described the floods in the early hours of Friday as a "100-year catastrophe" that "nobody expected."

At least 40 adults and 28 children were killed in the worst-hit Kerr County in central Texas, Sheriff Larry Leitha said Sunday, while at least 13 more people were killed by flooding in nearby areas. The death toll is expected to rise.

About 20 helicopters were taking part in the search for missing people in an area popular with campers that also hosted several summer camps for children.

Camp Mystic, one of the worst-hit, was an all-girl Christian camp where about 750 people had been staying with the floodwaters struck.

In a terrifying display of nature's power, the rain-swollen waters of the Guadalupe River reached treetops and the roofs of cabins as girls at the camp slept.

Blankets, teddy bears, and other belongings were caked in mud. Windows in the cabins were shattered, apparently by the force of the water.

Texas Governor Greg Abbott warned that more heavy rainfall could bring further flooding in Kerrville and surrounding areas, as officials cautioned people against going near still-raging rivers.

Months' worth of rain fell in a matter of hours on Thursday night into Friday, and rain has continued in bouts since then. The Guadalupe surged around 26 feet – more than a two-story building – in just 45 minutes.

Flash floods, which occur when the ground is unable to absorb torrential rainfall, are not unusual in this region of south and central Texas, known colloquially as "Flash Flood Alley."

Human-driven climate change has made extreme weather events such as floods, droughts, and heat waves more frequent and more intense in recent years.