After hours of waiting and praying in the attic, the water stopped rising and the family was rescued. A first responder helped Matteson, wearing a navy and pink floral dress and quilted white jacket, into the back of a car. Her family survived. Their home was not so lucky.

More than two dozen Mexican rescue volunteers and firefighters have been looking for victims and clearing debris along the Guadalupe River. Others were left waiting for visas and humanitarian permits to cross the border.

The Texas Hill Country has been notorious for flash floods caused by the Guadalupe River. Here's why the area is called "Flash Flood Alley."

On the night the deadly floodwaters raged down the Guadalupe River in Texas, the National Weather Service forecast office in Austin/San Antonio was missing a key member of its team: the warning coordination meteorologist,

Here's what to know about the deadly flooding, the colossal weather system that drove it and ongoing efforts to identify victims.

The risk of the catastrophic flooding that struck Texas Hill Country as people slept on July 4 and left at least 120 dead was potentially underestimated by federal authorities, according to an ABC News analysis of Federal Emergency Management Agency data, satellite imagery and risk modeling.

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.