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.

More than 100 people have been confirmed dead since July 4, when the Guadalupe River in central Texas swelled overnight and triggered flash floods that swept through an area known locally as “Flash Flood Alley.

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A Texas sheriff says the deaths from flash flooding in central Texas has risen to 27 people, including nine children. (AP video shot by: Lekan Oyekanmi)

With more than 170 still missing, communities must reconcile how to pick up the pieces around a waterway that remains both a wellspring and a looming menace.

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