Flash floods in Texas have killed more than 100 people, many of them children. Heavy rains fell quickly in the predawn hours Friday in 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.

Camp staff went to bed following what seemed like routine flood warnings. Within hours, they were fighting for survival. “Chaos struck almost instantaneously.”