In what experts call "Flash Flood Alley," the terrain reacts quickly to rainfall steep slopes, rocky ground, and narrow riverbeds leave little time for warning.

Flash floods surged through in the middle of the night, but many local officials appeared unaware of the unfolding catastrophe, initially leaving people near the river on their own.

Two days before flash floods on the Guadalupe River in Texas killed dozens of campers at a Christian girls summer camp, a state inspector approved operations, noting there was a written plan for responding to natural disasters.

Texas inspectors approved Camp Mystic’s emergency plan just two days before devastating floods killed over 27 people, mostly children, at the Texas summer camp

Eight-year-old girls at sleep-away camp, families crammed into recreational vehicles, local residents traveling to or from work. These are some of the victims.

Over 100 people have died after heavy rain pounded Kerr County, Texas, early Friday, leading to "catastrophic" flooding, the sheriff said.