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.

Heavy rain poured over parts of central Texas, dumping more than a month's worth of rain for places like San Angelo.

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.

When the precipitation intensified in the early morning hours Friday, many people failed to receive or respond to flood warnings at riverside campsites known to be in the floodplain.

At least 104 people are dead after heavy rain led to devastating flooding in Texas. Kerr County was hit the hardest, with at least 87 deaths, including 30 children. President Donald Trump signed a disaster declaration for the county and the Federal Emergency Management Agency is on the ground there.