Quicksand really can trap people

I had the definite impression that Quicksand's treachery was a Hollywood fantasy. Not quite so. True, one does not sink into the pit -- but neither is it at all easy to get out.

The Truth About Quicksand Is Beginning to Sink In - New York Times

... Sand grains in quicksand are usually loosely packed, with the clay acting as a fragile gel holding the grains together.

Hit with sudden force from, say, a hapless victim, the quicksand gel turns to liquid. Then salt causes clay particles to stick to one another instead of the sand grains, with the result that a victim ends up surrounded by densely packed sand.

The force needed to pull out a person immersed in quicksand is about the same needed to lift a car, Dr. Bonn said. The trick for escaping is to slowly wiggle the feet and legs, allowing water to flow in. People float in quicksand so it is also impossible to sink all the way in, but quicksand usually forms at river estuaries, so a captive could drown at high tide.

Now you know how to escape.