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.

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.

Local officials in one of the hardest-hit counties have still revealed little about what, if any, actions they took to safeguard residents, tourists, and visitors in an area known as “flash flood alley.