Le cri qui tue
C'était il y a sept ans, en Hollande, lors de la minute de silence à la mémoire des victimes de la seconde guerre mondiale. Soudain, un SDF se mit à crier. Mais ce n'est pas ce cri qui a créé la débandade, c'est le second, comme une réplique, poussé par une jeune fille qui a comme authentifié la nature inquiétante de ce cri. Résultat de la panique : 60 blessés et le SDF s'est retrouvé huit mois en prison.
Cela me fait penser aux explosions entendues au stade de France lors de l'attentat du Bataclan à Paris et qui, elles, sont restées sans réplique. Aucun signe de panique, le match a continué. Y eut-il eu la moindre incongruité de comportement que c'eût été catastrophique. Une foule est mise en effervescence par des signes indirects et correspondent à un manque de perception. On le voit bien dans cette vidéo, lors du premier cri, les gens restent impassibles : c'est juste un gars qui hurle pour une raison quelconque. Le second cri de la fille laisse penser qu'elle a été témoin de quelque chose d'horrible et là, l'imaginaire s'est mis à galoper comme une foule sait le faire, dans un état irrationnel et aveugle non canalisé.
The second scream was what actually tipped the stampede and got the ball rolling. The girl who started screaming about 5 seconds after the homeless guy is the one who validated the danger for the masses of people who were just trying to figure out what was happening.
The majority of people -- the ones who who were far away -- couldn't see the man and didn't panic when they first heard the scream, they just turned to try and see if it was a protester, a crazy guy, or a real threat. They would have been startled, but they were waiting for any evidence of real danger before panicking. When that first woman started screaming it validated the danger for a lot of people nearby her and convinced them to also cry out and run.
Everyone knows crowds are targets for terror attacks. They're rare, but massacres like the Boston Marathon bombing and Orlando nightclub do happen ... and any crowd can be a target. Because of this, anyone in the crowd who saw a few people near the commotion running or screaming would naturally accept that something really bad could be happening over there and try to move somewhere safe.
Unfortunately, since everyone was looking at the commotion, large groups of people would perceive danger at the about the same time. Their individual attempts to move towards safety would all seem to happen in unison and give rise to a collective force that moves like a fluid. Once a person is in this fluid they are surrounded and can't see anything. Everyone around them is moving in a reckless panic, but somehow they all keep getting packed closer and closer. Each individual starts to feel the inertia of the crowd carrying them forward with a frightening and unnatural energy. Their feet are being jostled now, its hard to stand but one wrong step will see them slip and be drawn under the tidal wave of pressure.
It bothers me a bit when I see someone imply that stampedes are just the result of people being stupid and that they wouldn't happen if people were more intelligent or rational [like them]. At what point did any of the people in this stampede have a choice to avoid it? If you go down and put your feet in the shoes of anyone near the middle of the crowd at the moment the guy starts screaming, you'll realize how little your reaction matters.