That's correct, in this morning's paper it stated the hikers went out not knowing that the storm began in a canyon above them and that the park service issued warnings for people to seek high ground. This happened so fast. They were a group from California and Nevada in their 40's and 50's.
It rained for only 30 minutes but the 1-1/2" created such water force that concrete bridge pillars were tossed around. This happened just south of Zion in the Hildale area. Two vehicles of 3 women and 13 children were swept away, killing all but 3 children.
Folks need to remember that in desert regions the rains can't soak in fast so the runoff goes into lower areas. It can rain hard 100 miles away and eventually that water collected along the way will appear and be deadly.
Full-Timed for 16 Years
.... Back in S&B Again
Traveled 8 yr in a 40' 2004 Newmar Dutch Star Motorhome
& 8 yr in a 33' Travel Supreme 5th Wheel