The key thing that was missing was any capacity by local officials to alert people beyond posting to X/Facebook in the middle of the night:

Rob Kelly, the Kerr County judge and its most senior elected official, said the county did not have a warning system because such systems are expensive, and local residents are resistant to new spending.

“Taxpayers won’t pay for it,” Mr. Kelly said. Asked if people might reconsider in light of the catastrophe, he said, “I don’t know.”