I know the hikers, so I had a feeling that were trying to climb Falling Rock Canyon b/c I took a group up there like 3 weeks ago. Definitely not a good weekend to try that.
"Trapped by darkness".....leads me to think maybe they did not have headlamps? Or got a late start? One reason I always carry a map w/me, I will know the approximate mileage and can plan when I should TURN AROUND.