My heart goes out to the victims and their families and friends. I guess they didn't understand the danger level and paid a horrible price for a misjudgment that would be easy to make.
That being said, I wouldn't have set foot in there even with a 1% chance! When I go in the slot canyons out at Mecca, I only go in the winter (no sudden monsoon type storms pop up here in the winter) with the sky clear and no rain forecast for the foreseeable future. The danger once you go in there is obvious. In the grottoes (an area of the slot canyons where the roof has collapsed and thus turned the slot canyon into a two ended cave, or roughly a tunnel) you can point your flashlight up 30 to 40 feet and see where recent flooding (within a year or two) had deposited brush and litter up there - indicating that the flood was 30-40 feet deep in there! They're amazing places to go, but I adhere to strict guidelines to avoid this sort of tragedy. I wish they had known just how great the danger really was. Here's a frightening video that turned out okay but illustrates the sudden, immediate danger that can arise:
https://www.youtube.com/watch?v=wj7WnkgjhM0
The video that follows this one was too sad for me to watch (I think, the title says they were swept away so I turned it off) but the one where the group escapes still shows how fast it built up. Terrifying, especially since they had their kids along with them. Great places to explore, but they are formed in violence and have deadly potential at certain times.
z
