Radar data can estimate rainfall to a fairly accurate amount. The rain data in the case of the deadly tragedy that unfolded in the Texas Hill Country last weekend shows exactly why the area around Camp Mystic and the Guadalupe River, outside of San Antonio, had such a raging flash flood.

At Camp Mystic, a Christian summer camp in Hunt, Texas, where officials are grieving the loss of 27 children and counselors, belongings of the young campers are strewn about the flooded floors of a dormitory, while other items, including a pink backpack and a Camp Mystic t-shirt, were found along the bloated Guadalupe River, photos show.