Do you remember the scene in "The Princess Bride" where Buttercup steps into the "snow sand" and Wesley has to jump in and rescue her? She disappears immediately in the quicksand, and Wesley dives in after her. That, and many other movies, depict quicksand as a pit where one quickly sinks to the bottom, suffocating in the sand.
Well, according to this article at National Geographic, the most a person would sink, even while struggling, is to about waist deep. The danger lies not in suffocation, but in getting stuck, so that when the tide comes in, you could drown.
So, how does one escape if stuck in quicksand? Do not have someone pull you; the researchers suggest that if friends tried to pull you out, they'd only succeed in pulling you "into two pieces if [they] try hard to pull [you] out." Instead, he continues, "The way to do it is to wriggle your legs around. This creates a space between the legs and the quicksand through which water can flow down to dilate [loosen] the sand. You can get out using this technique, if you do it slowly and progressively."
Now you know. And if you don't believe me, you can Google it.
XOXO,

BTW, for those non-Americans out there who have not seen this film, you really should. It is an American classic that children of my generation (Gen X or the Millennial Generation-- I think straddle both), were weened on.

