Over just two hours, the Guadalupe River at Comfort, Texas, rose from hip-height to three stories tall, sending water weighing as much as the Empire State building downstream roughly every minute it remained at its crest. The force of floodwater is often more powerful and surprising than people imagine.

Rescue efforts included over 2,100 responders on the ground, private helicopters, drones, boats and cadaver-detecting dogs.

Crews are digging through mountains of debris along the Guadalupe River as they continue their desperate search