On an evening in January A.D. 532, pandemonium broke out in the Constantinople Hippodrome, a U-shaped chariot racetrack surrounded by stadium stands. Two factions, the Greens and Blues—the predecessors of today’s soccer hooligans—broke into a fight. When the rest of the spectators dashed to escape, many became trapped by the rushing crowd, couldn’t reach the exits, and were trampled and killed. That incident was the start of the Nika riots that almost ended the rule of Eastern Roman emperor Justinian the Great.
Fifteen hundred years later, not much has changed. We still have stampedes, and still can’t get out of enclosed spaces properly. Since 2009, there have been fatal stadium stampedes in Morocco, Cote d’Ivoire, Bangkok, and Egypt. In their study of escape panic, Swiss physicist and sociologist Dirk Helbing concluded together with his colleagues that, “physical interactions in [a] jammed crowd add up and cause dangerous pressures… which can bend steel barriers or push down brick walls.”