(HRNW) – It happened at a music festival in Houston, a soccer stadium in England, during a hajj pilgrimage in Saudi Arabia, in a Chicago nightclub, and countless other gatherings: Large crowds surge toward exits, onto playing fields or press up against a stage with such force that people are literally squeezed to death.
And it has happened again, during Halloween festivities in the South Korean capital Seoul, where a crowd pushed forward, the narrow street they were on acting as a vice, leaving more than 140 people dead and 150 more injured.
The risk of such tragic accidents, which receded when venues closed and people stayed home due to the COVID-19 pandemic, has returned.
To be sure, most events where large crowds gather happen without injury or death, with fans coming and going without incident. But those that went horribly wrong shared some common traits. Here is a look at why that happens: