I guess this is why they refer to these events as “flash floods…”
…in the blink of an eye, a wall of water is crashing down on the troops…
If the water is arriving/moving that fast, I doubt one could out-run it… and of course we will have to wait ’til Monday to see whether they were swept away (or not!) Better save the MAP!
The Daily Trail 
You’d think the “professional guide” would know to always avoid hiking in an arroyo because of this very thing. Heck, anybody who has read “Westerns” knows this. Still, this is more or less a repeat of the killer bee crisis:
1. Leola talks to Mark about a suspicious situation (honey, wall of water)
2. Mark yells “Everybody run!”
3. Everybody runs with wall of doom in close pursuit.
You’d think that they would run UP the side of the arroyo, wouldn’t you?