How and Why Do Crowd Surges Become Deadly?

It happened at the Houston Music Festivalfootball stadium in England, during Hajj pilgrimage to Saudi Arabiain a Chicago nightclub and innumerable other gatherings: large crowds rush for the exits, onto the playing fields, or press against the stage with such force that people are literally squeezed to death.

And it happened again, during the celebration of Halloween in the capital of South Korea, Seoulwhere the mob surged forward, the narrow street they were on acted as a vice, killing more than 140 people and injuring another 150.

Such a risk tragic caseswhich retreated when venues closed and people stayed at home due to the COVID-19 pandemic, is back.

Certainly, most events that draw large crowds occur without injury or death, and fans come and go without incident. But the ones that went horribly wrong had some things in common. Here’s a look at why this happens:

HOW DO PEOPLE DIE AT THESE EVENTS?

While films showing crowds desperately trying to escape suggest that most deaths may be due to trampling, in reality most people who die in crowds are suffocated.

What cannot be seen are forces so strong they can bend steel. This means that something as simple as breathing becomes impossible. People die standing, and those who fall die because the body puts so much pressure on them that breathing becomes impossible.

“While people are struggling to get up, their arms and legs are twisted together. The blood supply to the brain begins to decline,” G. Keith Steele, visiting professor of crowd science at the University of Suffolk in England, told NPR after the Astroworld crowd surge in Houston last November. “It takes 30 seconds before you pass out, and for about six minutes you’re in a state of pressure asphyxiation. This is generally the cause of death – not crushing, but suffocation.”

WHAT IS THE EXPERIENCE OF BEING OPPRESSED BY PEOPLE?

Survivors tell stories of being suffocated, pushed deeper under what appears to be an avalanche of flesh as others clamber over them in a desperate attempt to escape. To be pressed against doors that won’t open and fences that won’t budge.

“Survivors described being gradually compressed, unable to move, their heads ‘clamped between arms and shoulders … faces gasping in panic,'” according to a report after the 1989 human devastation. Hillsborough Football Stadium in Sheffield, England, resulted in the deaths of almost 100 Liverpool fans. “They knew people were dying and they were helpless to save themselves.”

WHAT CAUSES SUCH EVENTS?

A Chicago nightclub erupted in 2003 after security guards used pepper spray to break up a fight. 21 people died as a result of the crowd surge. I this month in Indonesia131 people died as a result of the use of tear gas in a semi-closed stadium, causing a stampede at the exits.

In Nepal in 1988, a sudden downpour forced soccer fans to rush to the closed stadium exits, killing 93 fans. In the latest incident in South Korea, some news outlets reported that the hit-and-run occurred after a large number of people rushed to a bar after hearing that an unknown celebrity was there.

However, a British professor testifying as an expert witness in court cases involving mobs pointed to a variation on the old example of someone yelling “Fire” in a crowded movie theater. He told the AP last year that in the US, more than any other country, what would ignite such a rush for safety is the sound of something yelling, “He’s got a gun!”

WHAT ROLE DID THE PANDEMIC PLAY?

Stadiums are filling up again. During the pandemic, teams have taken some creative steps to keep things looking normal during games. Cardboard figures of fans were placed in some places and the noise of the crowd was heard — a sports version of a humorous show-laughter.

However, now the crowd is back and the danger is back.

“Once you add people into the mix, there’s always going to be risk,” Steve Allen of Crowd Safety, a British consulting firm that works with major events around the world, told the AP in 2021.