The official tally of storm-related deaths across Texas rose to 131 on Monday as authorities warned of yet another round of heavy rains 10 days after a Hill Country flash flood that transformed the Guadalupe River into a killer torrent.

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.

Texas Governor Abbott warns of more heavy rain as lawmakers launch probe into flood preparedness and emergency response failures.