We’ve all seen movies where someone gets stuck in quicksand, tries to call for help, but the more they struggle, the deeper they sink—until they’re completely swallowed. All that’s left is the sinister sand, and maybe their hat. In the 1960s, one in every 35 films featured quicksand.
Evidence of sinking deeper the more you struggle is still scarce. Quicksand is usually a mixture of sand or dirt and saltwater, commonly found in delta regions. The ground looks solid, but when you step on it, it liquefies. The water separates from the sand, leaving behind a trap of wet sand. The friction between the sand particles is greatly reduced, meaning it can no longer support your weight, and you begin to sink. So, does struggling really make you sink deeper until you’re buried and die?
John Dimech in his role in *Lawrence of Arabia* (1962)
Daniel Bonn from the University of Amsterdam saw warning signs about quicksand dangers while visiting Iran. He took some sand samples back, analyzed the proportions of clay, saltwater, and sand, and then recreated quicksand in the lab. Using aluminum beads with the same density as a human, he placed them on the sand to simulate a panicked person losing balance. He shook the whole model to see what would happen. Did the beads sink?
The answer was “no.” They did sink a bit at first, but as the sand gradually mixed back with the water, the buoyancy of the mixture increased, and they eventually floated back to the surface. Bonn and his team dropped various objects into their lab-made quicksand. Objects with a density similar to a human would sink, but none ever sank completely—only about half-way.
So if physics predicts you won’t keep sinking deeper, why do tragic accidents still happen occasionally, and people end up dying? For example, in 2012, a mother of two died while on holiday in Antigua after stepping into quicksand.
The reason is that even if quicksand doesn’t make you sink, if you aren’t rescued in time, rising tides can flood the area—and that’s when death awaits. That’s the real danger of quicksand.
So struggling alone won’t make you sink into quicksand, but we should still be cautious. If you want to save yourself immediately, rather than waiting for rescue teams or for the quicksand to liquefy again, according to Bonn’s research, it takes 100,000 newtons of force to pull out one foot—that’s like lifting a mid-sized car.
The quicksand effect means falling into a grain silo is often fatal
In experiments, Bonn’s team found that salt is a crucial component because it increases the instability of quicksand, leading to the formation of these dangerous thick sediment deposits. But later, another team from Switzerland and Brazil found that some quicksand doesn’t require salt. They discovered that bacteria can form a hard crust on the top layer of soil, giving the sensation of a stable surface—but when you step on it, the crust collapses. The good news is that such soil basins are rarely deeper than a person’s height, so even if someone steps into quicksand, they won’t drown.
However, dry sand is an entirely different story. The quicksand effect means that falling into a grain silo is often fatal.
In 2002, a report told the story of a man in Germany who fell into a grain silo at night. By the time rescuers figured out which of the eight silos he was in, the grain had reached his armpits. With each breath, his chest cavity decreased in volume, causing the grain to immediately fill the space and making it harder for him to breathe.
A doctor was lowered from the top with ropes to administer oxygen and secure a safety line. But soon the man began experiencing chest pain, diagnosed by the doctor as asthma triggered by dust. Rescuers came up with a clever solution: they placed a cylinder around the man and used an industrial vacuum to suck the grain away from his body, relieving the pressure so he could eventually be freed.
If you’re stuck in dry quicksand, you need outside help as quickly as possible; but if you’re stuck in wet quicksand—not submerged but trapped—what should you do? Gently wiggle your legs to let water seep into the sand around your feet, liquefying it again. The key is to stay calm (easier said than done), lean back to evenly distribute your weight, and wait to float to the surface.