The deadly floods that struck Texas on the 4th of July caught local officials off guard as the torrential rains caused the Guadalupe River to overflow in minutes.

At least 81 people are dead and at least 41 more are missing after devastating flash floods slammed Texas Hill Country, with water rescues taking place along the Guadalupe River, which rose rapidly early Friday morning to the height of a two-story building.

When too much rain falls for the ground to absorb, it runs downhill, pulled by gravity into streams, creeks and rivers.

(Reuters) -Founded by a University of Texas football coach, Camp Mystic where raging floodwaters swept away dozens of girls - killing several and leaving many others missing - was established along the banks of the Guadalupe River in central Texas hill country nearly a century ago "to provide young girls with a wholesome Christian atmosphere.