Also: San Antonio mourned the victims in a Travis Park vigil; UTSA said one of its teachers died in the Guadalupe River flood; Kerrville officials said a privately owned drone collided with a helicopter conducting search and rescue operations.

Flash flooding is common enough around the crescent-shaped region from Dallas through the Hill Country, the area earned the nickname "Flash Flood Alley."

A Texas sheriff says the deaths from flash flooding in central Texas has risen to 27 people, including nine children. (AP video shot by: Lekan Oyekanmi)

With more than 170 still missing, communities must reconcile how to pick up the pieces around a waterway that remains both a wellspring and a looming menace.

The region of Texas where flash flooding killed more than 90 people -- including dozens of campers -- is known for its tendency to experience flood emergencies.

Plans to develop a flood monitoring system in the Texas county hit hardest by deadly floods were scheduled to begin only a few weeks later.

At least 120 people have been found dead since heavy rainfall overwhelmed the river and flowed through homes and youth camps in the early morning hours of July 4. Ninety-six of those killed were in the hardest-hit county in central Texas, Kerr County, where the toll includes at least 36 children.

Follow for live updates in the Texas flooding as the death toll rises to 120, as rescue operations start to shift to recovery phase