When Crowds Kill: How Apps, Drones And Psychology Can Improve Crowd Control

A view of the dangerously packed crowd at the 2010 Love Parade
A view of the dangerously packed crowd at the 2010 Love Parade
Katja Heise

KAISERSLAUTERN - It's been more than two years since 21 people were killed and more than 500 injured in the Duisburg Love Parade, a tragedy that shocked Germany and reopened wider questions about how to control large crowds.

In an article published in the EPJ Data Science journal, physicist Dirk Helbing of the Swiss Federal Institute of Technology in Zurich (ETHZ) and his colleague Pratik Mukerjee have analyzed the disaster, which they blame on what’s known as the “crowd quake” or “crowd turbulence” phenomenon.

A crowd quake is the random turbulence or shock wave that can arise when many people are packed together. At occupancies of about seven persons per square meter, the crowd becomes almost a fluid mass. Shock waves can be propagated through the mass, sufficient to propel them distances of three meters or more,” found the scientists. In Duisburg that led to people falling over and being crushed as others trampled them. For their analysis, the scientists analyzed videos filmed by people who had attended the Love Parade and used computer-simulation.

But scientists were at work on ideas to make mass events safer well before the Duisburg catastrophe. The underlying problem in a crowd situation is that people begin to push and shove, creating a dangerous or even deadly situation, albeit unexpectedly and unintentionally. Physiological processes in the brain play a role. This depends in part on how alarm at the situation is processed by those involved – a slow and controlled build-up of fear reactions, or a full on, adrenaline-rush, fight or flight panic, which is catching. At some point a switch occurs between individual psychology and the conformity of mass psychology – with mass panic as the result.

Innovative design in buildings and stadiums can help counteract the resulting effects, Helbing says – for example the use of “wave breakers,” basically crowd retaining walls.

Another tool is the "Crowd Control" simulation model created by Siemens that was applied to a Klauserslautern soccer stadium holding 40,000 people and with few evacuation routes through the surrounding streets. Using monitors and analyzing crowd flows, the system was able to outline optimum evacuation routes for a number of different situations. "The police and fire departments have already incorporated the results into their evacuation plans," says Wolfram Klein, who heads the development of Siemens’s "Crowd Control" project.

At the London 2012 Olympics, police used an app-based Crowd Monitoring Technique developed by the German Research Center for Artificial Intelligence (DFKI) in Kaiserslautern.

"The great thing about the app is that if needs be every user can be sent a different message," DFKI expert Tobias Franke explains. One problem with the method is data protection – who really wants to make their details available to a state authority, especially if they are abroad? Franke says DFKI has thought of this, since optimum use of the app depends on getting a large number of people to use it and hence in winning their trust. So users remain anonymous, position data is encrypted and use is limited to the event area and only activated in critical situations.

"One problem in Duisburg was that more people gathered in some places than were expected," explains DFKI scientist Paul Lukowicz. Sensitive smart phones can however register even light surges that could lead to powerful waves of the type that led to the Duisburg disaster. Based on user information, personalized recommended escape routes could also be sent, for example not recommending a route that involves climbing over a wall to an older user.

Drones for aerial surveillance

The DFKI is presently working with organizers of Munich’s Oktoberfest, where it may be applied. Another possibility in Munich is drones for aerial surveillance, which according to the city’s fire department has the advantage of showing swelling crowds before they actually form so that prevention barriers can be set up.

Here too data protection is an issue – evaluation of the images would have to be based on crowd density only and not individual identities, although that would theoretically not be a problem since vertical filming would not make faces identifiable. Advantages include being able to identify the fastest way for an ambulance or the police to get through.

The first test run with drones in Germany took place at the Bochum Total street festival in July, when the AirRotorMedia company working at the behest of the fire department and researchers at the University of Paderborn filmed 600,000 people from a height of around 100 meters (328 feet).

"Picture quality was very good," says Stefan Lieber of the Bochum Fire Department. Not only were the drones cheaper than police helicopters, they had more technical advantages and it is virtually impossible for them to crash – it they lose radio contact or the batteries are on the blink they return automatically to launch site.

Drones made and run by the University of Technology in Kaiserslautern and researchers in the city’s Fraunhofer Institute for Experimental Software Engineering may be in use at the world soccer championships in Brazil in 2014. The idea is to incorporate their input with that of stationary cameras, smart phone apps and more into a kind of electronic situation table where it can all be evaluated.

However intensively researchers work on new crowd control technologies, the ETHZ’s Helbing cautions, "Absolute security will never exist – you cannot categorically exclude the possibility of accident."

Globalization also means that visitors at major events are increasingly heterogeneous and that can have an effect on behavior – and hence relevant security measures. Cultural differences have to be taken into account also. Another current avenue of global research is the study of how different peoples react in crowd situations.

In Germany, a number of fire departments, the Jülich Research Center and the University of Wuppertal are focusing on how catastrophes like the one in Duisburg could be avoided in future. Everything from training methods and simulation instruments to systems to develop security concepts are being developed. The goal is the creation of a manual for organizers of large-scale events. But researchers point out that wading through all the ordinances governing public events can complicate the endeavor – not to mention that there is no single definition of “large scale event.” Getting that defined at federal level would be a big help, they say.

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Queen Elizabeth II with UK PM Boris Johnson at a reception at Windsor Castle yesterday

Anne-Sophie Goninet, Jane Herbelin and Bertrand Hauger

👋 Hej!*

Welcome to Wednesday, where chaos hits Syria, Brazilian president Jair Bolsonaro is accused of crimes against humanity and a social media giant plans to rebrand itself. For Spanish daily La Razon, reporter Paco Rodríguez takes us to the devastated town of Belchite, where visitors are reporting paranormal phenomenons.



• Syrian violence erupts: Army shelling on residential areas of the rebel-held region of northwestern Syria killed 13 people, with school children among the victims. The attack occurred shortly after a bombing killed at least 14 military personnel in Damascus. In central Syria, a blast inside an ammunition depot kills five soldiers.

• Renewed Ethiopia air raids on capital of embattled Tigray region: Ethiopian federal government forces have launched its second air strike this week on the capital of the northern Tigray. The air raids mark a sharp escalation in the near-year-old conflict between the government forces and the Tigrayan People's Liberation Front (TPLF) that killed thousands and displaced over 2 million people.

• Bolsonaro accused of crimes against humanity: A leaked draft government report concludes that Brazilian President Jair Bolsonaro should be charged with crimes against humanity, forging documents and incitement to crime, following his handling of the country's COVID-19 pandemic. The report blames Bolsonaro's administration for more than half of Brazil's 600,000 coronavirus deaths.

• Kidnappers in Haiti demand $17 million to free a missionary group: A Haitian gang that kidnapped 17 members of a Christian aid group, including five children, demanded $1million ransom per person. Most of those being held are Americans; one is Canadian.

• Putin bows out of COP26 in Glasgow: Russian President Vladimir Putin will not fly to Glasgow to attend the COP26 climate summit. A setback for host Britain's hopes of getting support from major powers for a more radical plan to tackle climate change.

• Queen Elizabeth II cancels trip over health concerns: The 95-year-old British monarch has cancelled a visit to Northern Ireland after she was advised by her doctors to rest for the next few days. Buckingham Palace assured the queen, who attended public events yesterday, was "in good spirits."

• A new name for Facebook? According to a report by The Verge website, Mark Zuckerberg's social media giant is planning on changing the company's name next week, to reflect its focus on building the "metaverse," a virtual reality version of the internet.


"Oil price rise causes earthquake," titles Portuguese daily Jornal I as surging demand coupled with supply shortage have driven oil prices to seven-year highs at more than $80 per barrel.



For the first time women judges have been appointed to Egypt's State Council, one of the country's main judicial bodies. The council's chief judge, Mohammed Hossam el-Din, welcomed the 98 new judges in a celebratory event in Cairo. Since its inception in 1946, the State Council has been exclusively male and until now actively rejected female applicants.


Spanish civil war town now a paranormal attraction

Ghosts from Spain's murderous 1930s civil war are said to roam the ruins of Belchite outside Zaragoza. Tourists are intrigued and can book a special visit to the town, reports Paco Rodríguez in Madrid-based daily La Razon.

🏚️ Between August 24 and September 6, 1937, during the Spanish Civil War, more than 5,000 people died in 14 days of intense fighting in Belchite in north-eastern Spain, and the town was flattened. The fighting began on the outskirts and ended in house-to-house fighting. Almost half the town's 3,100 residents died in the struggle. The war annihilated centuries of village history. The town was never rebuilt, though a Pueblo Nuevo (or new town) was built by the old one.

😱 Belchite became an open-air museum of the horror of the civil war of 1936-39, which left 300,000 dead and wounds that have yet to heal or, for some today, mustn't. For many locals, the battle of Belchite has yet to end, judging by reports of paranormal incidents. Some insist they have heard the screams of falling soldiers, while others say the Count of Belchite wanders the streets, unable to find a resting place after his corpse was exhumed.

🎟️ Ordinary visitors have encountered unusual situations. Currently, you can only visit Belchite at set times every day, with prior booking. More daring visitors can also visit at 10 p.m. on weekends. Your ticket does not include a guaranteed paranormal experience, but many visitors insist strange things have happened to them. These include sudden changes of temperature or the strange feeling of being observed from a street corner or a window. Furthermore, such phenomena increase as evening falls, as if night brought the devastated town to life.

➡️ Read more on Worldcrunch.com


We still cling to the past because back then we had security, which is the main thing that's missing in Libya today.

— Fethi al-Ahmar, an engineer living in the Libyan desert town Bani Walid, told AFP, as the country today marks the 10-year anniversary of the death of dictator Muammar Gaddafi. The leader who had reigned for 42 years over Libya was toppled in a revolt inspired by the Arab Spring uprisings and later killed by rebels. Some hope the presidential elections set in December can help the country turn the page on a decade of chaos and instability.


Iran to offer Master's and PhD in morality enforcement

Iran will create new "master's and doctorate" programs to train state morality agents checking on people's public conduct and attire, according to several Persian-language news sources.

Mehran Samadi, a senior official of the Headquarters to Enjoin Virtues and Proscribe Vices (Amr-e be ma'ruf va nahy az monkar) said "anyone who wants to enjoin virtues must have the knowledge," the London-based broadcaster Iran International reported, citing reports from Iran.

The morality patrols, in force since the 1979 revolution, tend to focus mostly on young people and women, particularly the public appearance for the latter. Loose headscarves will send women straight to a police station, often in humiliating conditions. Five years ago, the regime announced a new force of some 7,000 additional agents checking on women's hijabs and other standards of dress and behavior.

Last week, for example, Tehran police revealed that they had "disciplined" agents who had been filmed forcefully shoving a girl into a van. Such incidents may increase under the new, conservative president, Ibrahim Raisi.

Speaking about the new academic discipline, Samadi said morals go "much further than headscarves and modesty," and those earning graduate degrees would teach agents "what the priorities are."

Iran's Islamic regime, under the guidance of Shia jurists, continuously fine tunes notions of "proper" conduct — and calibrates its own, interventionist authority. More recently the traffic police chief said women were not allowed to ride motorbikes, and "would be stopped," Prague-based Radio Farda reported.

Days before, a cleric in the holy city of Qom in central Iran insisted that people must be vaccinated by a medic of the same sex "as often as possible," and if not, there should be no pictures of mixed-sex vaccinations.

✍️ Newsletter by Anne-Sophie Goninet, Jane Herbelin and Bertrand Hauger

Thoughts on Facebook's new name? Zuckerverse? Tell us how the news look in your corner of the world: Drop us a note at info@worldcrunch.com!

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