The death toll, as of Sunday at 10 p.m., of 81 fatalities, makes the Central Texas flash floods on July 4 the second-deadliest flood disaster in Texas history.

The Hill Country is notorious for flash flooding, given the high number of narrow valley floors and proximity to potential tropical events from the Gulf. This event was partly triggered by the remnants of Tropical Storm Barry that hit Mexico on Sunday, June 29.

The atmosphere was loaded with water vapor from Berry that moved north into the middle parts of Texas.

More than a foot of rain fell in less than a 12-hour period starting Thursday and going into Friday morning. This massive rain fell over a large part of the western Guadalupe River basin. Kerrville and west into the town of Hunt are the headwaters of the river.

The destructive fast-moving waters rose 26 feet in just 45 minutes before daybreak Friday, washing away homes and vehicles. The danger was not over as torrential rains continued to pound communities outside San Antonio on Saturday, and flash flood warnings and watches remained in effect. 

Searchers used helicopters, boats and drones to look for victims and to rescue stranded people in trees and from camps isolated by washed-out roads. 

"People need to know today will be a hard day," Kerrville Mayor Joe Herring, Jr. said Saturday. "Please pray for our community." 

President Trump signed a major disaster declaration for Kerr County on Sunday morning, as Abbott visited flood-damaged areas. Abbott encouraged all Texans to pause in reflection and prayer Sunday, and to also "seek God's wisdom, peace, and mercy in this time of need for so many Texas families." 

On Saturday, Abbott said that 850 people had been rescued in the past 36 hours. 

Rescuers scoured flooded riverbanks littered with mangled trees Saturday and turned over rocks in the search for more than two dozen children from a girls' camp and many others missing after a wall of water blasted down a river in the Texas Hill Country. Martin said there are still unidentified victims at funeral homes that include adults and children.

At least 81 people are dead and at least 10 are still missing from Camp Mystic in Kerr County, a children's summer camp, officials said Sunday. 

Col. Freeman Martin with the Texas Department of Public Safety said Sunday that there is "no higher priority than finding those children."