“, reports Mehdi Moussaid, researcher specializing in crowd behavior at the
At gatherings of very large crowds, “
the slightest lack of organization can quickly turn into a nightmare“.
The “crowd tremor”
What happens during a crowd movement? The dynamics of this phenomenon were only understood quite recently, in 2006, following a large-scale stampede that caused the death of 362 people in Mecca. The accident was filmed by a surveillance camera whose images were analyzed in the laboratory of German physicist Dirk Helbing.
Thanks to this video, this researcher specializing in crowd behavior identified the phenomenon of “crowd shaking” (“ crowd quake“).
This is a collective phenomenon that sets in spontaneously when the density of individuals reaches a critical threshold of around 6 people per square meter. At this level of crowding, physical contact between bodies is so intense that the slightest movement triggers a wave of jostling that spreads through the crowd. It is these shock waves, similar to the tremors that occur during an earthquake, that cause people to fall and experience crushing physical pressures.»
Since this important discovery, crowd tremors have been systematically identified during deadly stampedes like that of the Love Parade. And even if they are better and better understood, no solution exists to date to stop this phenomenon once it is in place.»
What to do “
when you are a prisoner of the crowd, the noose tightens and the tremors begin to be felt?Here are Mehdi Moussaid’s survival tips developed thanks to the research of “fouloscopy” laboratories.
open your eyes
“Your first objective will be to extract yourself from the mass as quickly as possible. Look around you: is it better to turn around or keep going? To find out, try to estimate where the epicenter of the stampede is, where the crowding is at its greatest, and head in the direction where the density is gradually decreasing. Also remember to look up. You might find a quick escape by scaling a barrier or climbing onto a bar counter.
Leave while there is still time
As the density increases around you, the available space decreases and your freedom of movement gradually decreases. The longer you wait, the harder it will be to escape. Time is on your side. Therefore, do not hesitate to leave the area of heavy congestion as soon as you start to feel uncomfortable, and as long as you still have enough room to move around.
By removing yourself from the heart of the crowd, you will also reduce the risk of accidents for others, because your absence will have the effect of reducing congestion for those who stay behind.
If it’s too late to flee, you will have to adapt. The most important recommendation then will be to keep the balance. Stay on your feet, at all costs, at the risk of finding yourself in a critical situation. During a crowd movement, the proximity of individuals is such that your fall would immediately cause that of your neighbors by domino effects. Before you can get up, the weight of the bodies will immobilize you on the ground. So stay up! For example, pay particular attention to backpacks and other abandoned objects that could throw you off balance.
Save your oxygen
Oxygen will be your most precious resource, the one that will run out if the situation worsens. Indeed, the vast majority of deaths are caused by asphyxiation. For example, avoid shouting if it is not essential, and control your breathing as much as possible.
Fold your arms
I discovered this technique by reading the reports of Paul Wertheimer, a businessman at the head ofCrowdsafe, a crowd management consulting firm. And that’s actually a good idea. When the pressure becomes too intense, fold your arms in front of you, like a boxer. In this position, you will be able to protect your rib cage and preserve a few centimeters of space around your ribs and your lungs.
Let yourself be carried by the wave
The natural instinct when being pushed around is to resist the pressure by pushing in the opposite direction. In the case of a crowd movement, this is a bad idea. You will not be able to thwart a shock wave by the strength of your arms alone. The pressure from the crowd will get you carried away no matter what you do. Resisting would therefore be a vain use of your precious energy. In addition, it would risk amplifying physical tensions, making the next waves even more intense. On the contrary, rather let yourself be carried by the flow by simply trying to keep your balance.
Get away from the walls
The only place where the previous advice cannot be applied is near a wall, a fence or any other solid object. The case studies indeed show that the proximity of an obstacle is an important source of danger. The first victims of a stampede are often crushed against a wall, as was the case during the panic movement in Turin in 2017 or during the Heysel and Hillsborough tragedies in the 1980s. Our numerical simulations show that the most intense are exerted in the vicinity of a solid obstacle. As far as possible, stay away from walls, posts and fences.
Know how to interpret density signals
To make the right decisions, it is important that you can assess the seriousness of the situation. But what can you do without a measuring instrument, when you yourself are immersed in the mass? Here are some simple rules for estimating the density around you:
If you have no physical contact with your neighbours, you are probably still below 3 people/m2, there is no risk.
If you accidentally touch one or two of your neighbors at the same time, the density should be between 4 and 5 people/m2. There is no immediate danger, but it would be better to start slowly moving away from the heart of the congestion.
If your arm movements are so restricted that you find it difficult to bring your hand up to your face. There are too many people. Go!
In case of panic
Panic is a special case in which the crowd rushes in the same direction to flee from a real or suspected danger. In recent years, the terrorist threat has caused a sharp increase in this type of collective movement, as on the Place de la République in Paris in November 2015, on the Place San Carlo in Turin in June 2017, or on the Cours Saleya in Nice in July 2018.
Keep in mind in these situations that the movement of the crowd can be more dangerous than the threat you are fleeing. Therefore, give yourself a short time to assess the nature of the danger and walk away calmly, staying as far away from the crowd as possible.
If the situation is serious for you, it is just as serious for the people around you. Studies by psychologist John Drury of the University of Sussex in England have repeatedly shown that altruism and mutual aid are important ingredients in avoiding tragedy. A united crowd has a better chance of survival than a crowd of individualists. So, stay human and benevolent towards others by offering your help when you can, avoiding causing the downfall of your neighbors and watching over the weakest. Everyone will benefit, including yourself. »
For more information, see the links below.
Psychomedia with source: The Conversation.
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