Emergency officials are starting to focus on alert systems as they search for answers about how the flash flooding swept away so many.

Flood watches have been issued by the National Weather Service until at least 7 p.m. CT July 6 in Hill Country and along the I-35 corridor. The Weather Prediction Center added that scattered thunderstorms are likely to drop "torrential downpours over sensitive soils across parts of the Texas Hill Country."

The heavy rain that turned a river in Texas into a raging wall of water was fueled by unique atmospheric conditions, according to meteorologists and climate scientists.