In the early hours of Independence Day, rain pelted sleeping communities in central Texas. No one knew yet how devastating the storm would become.

Entire neighborhoods vanished in flash flooding throughout the weekend, while residents and campers were swept away in the surging waters.

The death toll across the state eclipsed 100 by Tuesday, and search and rescue efforts persist.

As communities continue recovering from the catastrophic floods, questions swirl around how this tragedy happened.

Several compounding factors made the flooding in central Texas a worst-case scenario.