Crowds can occur in many different places and in many forms. Whether it’s at a football match, a concert, or a local party, any number of people who congregate together can be defined as a crowd. Crowds can pose hidden dangers that you may have never considered. Suffocation and trampling are common instances where being in a crowd can go wrong; as well as this, calmer crowds that are moving at a regular pace can become a fluid-like procession that can crush or propel people into the air.
The UK based technology firm, Oasys Software, provides MassMotion technology that allows users to analyse pedestrian movement and crowds to ensure architects design environments that are as safe as possible for their users. This technological innovation aids event organisers because they are legally obliged to consider the welfare of the people that make their events happen. What the government considers the dangers of a crowd are:
- People crushed against each other.
- Being crushed against something fixed such as a barrier.
- Being trampled on.
- Surges, swaying, or a rush of people.
- Aggressiveness towards others.
- Behaviour deemed dangerous such as climbing and throwing.
The real dangers in a crowd
Although it may not be commonly known, trampling is very rarely the main cause of death during a crowd disaster. Rather, a vast quantity of people moving at a pace can exert up to 4500 Newtons, or 1000lbs of force. If you consider that the force of a crowd can bend steel railings, you begin to understand the danger. During a disaster, suffocation can be induced as a result of that kind of force being inflicted upon the chests of members of the crowd.
It’s not always a ‘stampede’ that causes these types of deaths. Instead, high concentrations of bodies such as those consisting of 6 or more people per square meter can cause deaths if someone trips over. If the movement of a crowd was free flowing enough to physically engage in a stampede, then there would be technically enough room to move out of way. It is the lack of room, and not the speed of the crowd, that causes deaths.
Take the example of the Ibrox Disaster in 1971, which killed 66 people when somebody tripped over on the stairwell when leaving the stadium. As a result of their fall, people began piling up from the rear of the stairwell, leading to many people at the front suffocating.
One of the main problems when things start to go wrong in a crowd is the crowd’s reaction. However, this is not to confuse this reaction with panic, because it would be a very reasonable way to feel during this type of situation. For example, in 2003, a crush in a Chicago nightclub happened as a result of people trying to get out of the way of pepper spray being used to disrupt a fight. Unlike a situation that represents mass panic, these situations become more coordinated but still lead to fatalities due to the amount of people involved.
A crowd that wants to reach a focal point, such as the front of a stage, can cause a ‘craze’. In 1990, 1426 worshippers were killed during a crush as they tried to reach a place of worship within a 500-metre-long tunnel, and innocent but tragic loss of life by accident.
By thinking of a crowd as a head and body, then a breakdown in communication between the head and body can cause problems. Even when the head of a crowd (the front) is in distress, the body (nearer the back) may push forwards if they are still unaware of the distress that they’re in. When people are being crushed, this can still create the illusion of forward movement; the body of a crowd is an innocent force that can ultimately lead to crushing at the front because they are unaware of what is going on.
Examples of danger
Displaying the factors previously discussed, there are many examples of when large crowds have ended in disaster.
- No communication: In 1981, when trying to leave a football match in Athens stadium, large crowds went to leave the venue and found that the gates were locked. The back of the crowd did not know this and consequently 24 people died.
- ‘Crazed’ behaviour: Commonly known as the Hillsborough disaster, in 1989 96 people were killed and 170 were injured at Hillsborough Stadium, Sheffield. As a result of an unanticipated amount of people entering the ground, security opened gates to negate excessive crowd pressure. However, many fans began to surge the stadium, which crushed fans within the terraces with nowhere to go.
- Reaction: Resulting from a riot between English and Italian fans during the European Cup Final of 1985 in Brussels, 38 deaths occurred and 437 people were injured when people attempted to escape the violence. They died as a result of asphyxia.
How to prevent these dangers
Attempting to prevent crowd disasters is actually an incredibly difficult task; the factors that contribute towards these events are complex. However, setting a limit on the amount of guests that can be at an event is one way of alleviating the problems inherent within a disaster of this kind. However, this can be difficult to manage at large events like religious gatherings.
Communication is also something worth bearing in mind. Barriers and paths that are used to avoid crowd surges can often contain their own potential dangers. Barriers that can’t crush people are often the most effective mode of directing a crowd. Stewards can also help to direct crowds in the right direction, this stops the breakdown of communication that is so common between the head and body of a crowd.
Perhaps the most vital of preventatives when it comes to crowd disasters is the assurance of being able to gain access to the exits provided. Allowing different proportions of a crowd to leave at different times, is also a good way of assuring nobody is crushed in a crowd.
Preventative technologies such as MassMotion are leading the way in fighting against crowd disasters in the future. Organisations that are responsible for the maintenance of buildings and the crowds within them should conduct stress tests, which could lead to more thorough and strategic planning method to design escape routes that will stop these disasters from happening.
Sources:
http://www.bbc.co.uk/programmes/b00x53wd
http://www.gkstill.com/ExpertWitness/CrowdDisasters.html
http://www.crowdsafe.com/fruincauses.pdf