Mecca Stampede Shows How Crowds, Usually Calm in Crisis, Can Panic

By BENEDICT CAREYSEPT. 24, 2015 NYT

Contrary to common portrayals of the madding crowd, people caught in an unfolding catastrophe usually summon their best selves, keep cool heads and look out for those around them, according to decades of research into crowd reactions during earthquakes, fires, floods, bombings and other threats.

It had not been reported exactly what touched off the panic that killed more than 700 people on Thursday near Mecca, Saudi Arabia, or whether deficient crowd-control measures might have been to blame.

Even so, the disaster is a reminder that in some circumstances, the strong social roles that help preserve lives in most crises can break down.

The huge number of hajj pilgrims — an estimated two million this year — probably played a role, especially since the area around Mecca would not be familiar ground for most of them. Sheer numbers can overwhelm a person’s sense of space, of where you are and where you are going.

“There’s absolutely no sense of shared infrastructure” in such a situation, said Lee Clarke, a sociologist at Rutgers University and author of “Worst Cases,” a history of crowd behavior in the face of threat and catastrophe. By contrast, he said, “you can have 40,000, 50,000 or 80,000 people trying to exit a football stadium at the same time, and people know how to act in that system because there’s a shared sense of where the ramps are leading, where the exits are, where the gates are.”

How the Hajj Stampede Unfolded

Maps showing where more than 700 people were killed in a stampede near Mecca, Saudi Arabia.

OPEN Map

Research by Dr. Clarke and others has confirmed what most people feel instinctively when they are in a tightly packed and nervous crowd: If escape routes are blocked or dwindling, fear begins to color every decision. Caught in the middle of a large enough crowd, people may see no way out.

That was apparently a cause of a mass panic that killed 21 people at a music festival in Duisburg, Germany, in July 2010, Dr. Clarke said. Police officers at the festival tried to reverse the flow of a crowd, and people were trapped near a tunnel entrance, unable to move in any direction, according to reports on the event.

Another instance occurred in Cincinnati before a 1979 concert by the Who. Fans outside the arena who were afraid the concert was starting without them swarmed toward a row of entrance doors and panicked when the doors were kept locked, shutting off any escape for those at the front of the crowd. Eleven people died in the shoving.

The composition of the crowd can also be a factor. Large religious events tend to attract thousands of people who are elderly and have difficulty bearing the heat, the fatigue and the jostling of crowds. Government scientists in India found in a recent study that almost 80 percent of “mass gathering emergencies” in that country occurred during religious festivals.

In a large crowd, other dynamics that undermine social collaboration can develop, especially when the crowd is culturally diverse and in motion.

One is a surge with no apparent cause. It may have originated hundreds of yards away with a bit of pushing, or even simply people stopping to rest, but it can amplify and reach most of the crowd like a rogue wave, powerful and seemingly random.

“Think of being in traffic on the highway, stopping and starting, and there’s no accident, no police, no source at all,” said George Loewenstein, a professor of economics and psychology at Carnegie Mellon University. “In large crowds, especially if they’re somehow contained, a small disruption in one place can cause larger chaos far away, for reasons no one there understands.”

People’s natural instinct toward social cohesion may be weaker in some crowds than others, research suggests. Anthony R. Mawson of Jackson State University found that people’s behavior in mass panic events depends in part on the whereabouts of “familiar persons,” meaning friends and family.

“Their physical presence has a calming effect and reduces the probability” of a fight-or-flight response, he concluded, “while their absence has the opposite effect.”

People who have been caught at packed events like rock concerts know that this instinct can extend to other fans nearby, the clutch of 10 to 20 people who may bond, if temporarily, during a show. The vast diversity of the crowds near Mecca, with pilgrims from all over the world, may make such spontaneous groups less likely to form there.

“This is such a heterogeneous mass of people, of all different ages, languages and cultures,” Dr. Loewenstein said. “Despite the shared religion, communication could have been very difficult.”

Little sense of space, no clear escape, rogue waves of motion among people who have difficulty communicating — those are conditions when collaboration can turn to desperation, and blind panic can spread.