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.

Flash flood alley is a curved-shaped region about 300 miles long and 50 miles wide in central/south-central Texas, extending from north of Dallas to southwest of San Antonio. Its location, weather patterns, and geology often combine to create devastating floods.

The search for survivors continues in central Texas after a wave of floodwater filled camp cabins to their roofs, trapped people in trailer homes and overwhelmed cars before dawn on the Fourth of July.