The risk of the catastrophic flooding that struck Texas Hill Country as people slept on July 4 and left at least 120 dead was potentially underestimated by federal authorities, according to an ABC News analysis of Federal Emergency Management Agency data, satellite imagery and risk modeling.

As the search for victims continues, county officials say "additional resources" are being deployed as the "mission efforts become more technical."

Nearly a week after deadly floods struck Central Texas, search and rescue teams are continuing to probe debris for those still missing.