When storms roll in, water rushes downhill fast, gaining speed and force as it moves — often with deadly results.

Camp Mystic, a Christian girls' camp, reported that they lost 27 campers and counselors in the devastating floods, with 11 still missing. Several of the victims were from the Houston area.

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.