Football matches, concerts and festivals are just a few of the events that attract crowds of people. While the majority of guests attending these events are there to simply have a good time, they are unaware that they have exposed themselves to something that has the potential to be extremely dangerous. Mass crowds can cause suffocation, trampling and riots to name a few dangers.
MassMotion software, provided by Oasys Software, can be used to analyse crowd management and pedestrian flow so that architects can use the data to design safer environments to minimise the risk of crowd disasters. With that in mind, event organisers have a legal duty to ensure they do their best to try and prevent some of the dangers as outlined by the Government:
- Crushing between people.
- Crushing against fixed structures such as barriers.
- Surging, swaying or rushing.
- Aggressive behaviour.
- Dangerous behaviour such as climbing on equipment or throwing objects.
The actual dangers in crowds
Suffocation, as a result of crushing is the leading cause of death in crowd disasters. In large crowds, forces can reach over 4,500 Newtons. The head of the crowd feels all that pressure while being crushed against the steel railings. As the steel railings bend with the force, those who are pressed against them suffocate from the pressure on their chest (asphyxia).
It is rare that a stampede causes this kind of disaster, as a stampede requires room for people to move over each other. There are three main causes of this kind of crush:
- A minor fall or trip, causing a delayed chain reaction through the crowd.
- A group reaction to a perceived threat.
- Crazed behaviour where the crowd rush to attain a valued object.
In most of these cases, a lack of communication can be held partly responsible. When a lack of communication is present, there are no ways to pass the message from the rear and body of the crowd to the head of the crowd and vice versa. As the front of the crowd begins to collapse, they cant send the warning backwards, so instead the rear of the crowd gets the illusion of progressive movement in the crowd so continue to push causing disastrous consequences.
There are a number of crowd disasters which all displayed signs of the factors discussed above.
Lack of communication:
In 1981, many Greek football fans were killed when they tried to leave a match in Athens stadium, finding the gates locked. The rear of the crowd had no way of knowing the situation and the head of the crowd was unable to communicate information so the rear continued to press forward, causing 24 deaths.
In 1989, 96 people were killed and more than 170 injured at Hillsborough Stadium in Sheffield, England. A larger than expected fan base tried to enter the stadium before the football game began, so the police opened the turnstiles to speed up the process. As a result, fans without tickets also surged into the stadium, crushing fans into enclosed terraces.
Reaction to perceived threat:
At a European Cup Final in Brussels in 1985, a riot by English and Italian led to spectators trying to escape the violence, which led to 39 deaths by asphyxia and over 437 people were injured.
Actually preventing crowd disasters can be very difficult as the causes can be complex. The density of the crowd should be the first issue to tackle by limiting the number of guests at an event, you can take control over the crowd density. However, some events like religious gatherings can be hard to control.
You can improve the communication by hiring stewards to be based at different points of the crowd between the rear and the head. Also, by creating movement paths with rope instead of steel barriers, the stewards can keep track of any issues between sections of the crowd.
For crowd surges, its vital to ensure proper access and exits are in place. A timed exit in a large event, where people from different levels exit at different times, is another popular prevention method.
Technology is also helping fight against crowd crushing and other dangers. Using tools like MassMotion, those in charge of buildings or crowd control should first run simulations to test the stresses of pedestrian flow and crowds. These tools can help in evacuation planning, giving an unparalleled insight into the unique spectacle of crowd movement.