The Koh Pich Disaster – Preventable?

It goes without saying that everybody is shocked by this event and feels with the families and friends of those who lost their lives on that fateful night.

The headline might suggest that I am going to engage in a round of finger pointing or seeking out responsible parties - I am not; it wouldn’t be my place anyway. Of course, it would be very easy to put the blame on someone in order to divert from the real issue underlying such a stampede. Once you have a culprit the case is closed for most people. It is just like in a murder trial. The killer gets a life sentence or even the death penalty; that is supposed to bring closure (what a nice word) to the victim’s family. But does it? I don’t think the families of the victims in this case would feel less pain if they knew why all this happened. Their son or daughter, or niece, or nephew, is gone and won’t return.

The answer to the question is obviously not so easy. Although I am not an expert, I dug into the subject matter and was shocked at how many of those stampedes actually happen every year. Just check out http://en.wikipedia.org/wiki/Stampede, which incidentally had added Koh Pich just one day later. We are swamped by news stories every day so much that we don’t seem to notice any more how many people die in such a horrible way. Sure enough, this story had disappeared from international headlines just one day later, to be replaced by a missile attack in the Koreas. How are we supposed to keep up with all this news stream?

This stampede appears to be very similar to the one that happened in Germany this past summer at an event called ‘Love Parade’, a huge rave concert. The number of fatalities was thankfully ‘only’ 21. Instead of too narrow a bridge as the access/exit route to a site there it was tunnel. In both cases these two entry/exit points became the proverbial bottleneck, which when people move in panic becomes like moving walls in a horror movie. People are pressed against each other, which makes them move even faster in order to get away from all that pressure.

Many studies have been done on the subject and there is a very logical and scientific explanation of people’s behavior and why it comes to stampedes. I found one done by the Technical College for Sociology in Zurich. The gist of it is as follows.

There is something called average density, meaning the number of people on a certain area at a given time, which generally is considered to be four per square meter. Once the number reaches six a critical point has been reached, at which people start to feel uncomfortable and try to avoid this by moving away. If there is enough room to move to, of course, there is no imminent danger. Under normal circumstances, that critical density is of no direct consequence as the people either move to or from an event in a more or less orderly fashion unless there is something that makes people want to move faster than is possible due to local density.

By news accounts the Koh Pich root cause that provoked the panic was a slight swaying of the suspension bridge due to the masses moving on it, which led some people to believe that it was about to collapse. This thought spread through the masses like wildfire. People reportedly started moving in both directions increasing the local density to over eight people. At the critical point of six people per square meter the speed of movement is decreased threefold, in other words, they almost come to a complete stop. Meanwhile more people press on, trying to get away from the purported danger point.

Now one has to realize that such a density can result in forces to over 445 kg being exerted in one direction. In this enormous pressure, people have trouble breathing that adds to the panic and they futilely try to move even more quickly, resulting in possible thrashing about. Eventually and consequently, many of them lose consciousness and die by asphyxiation (compressive asphyxiation as per Wikipedia). They are literally crushed to death. They then fall to the ground and are trampled on by the masses above them.

Now are those stampedes preventable? At first glance one tends to say ‘yes’. This is actually the point where the local authorities with their responsibility for public safety come in. Usually, such an event needs some kind of official permission to take place. In Koh Pich the Bayon concert and all the other attractions most certainly did have all their permits in place. The authorities estimated that about 2 million people converged on Phnom Penh for the water festival, the biggest event every year. Some previous estimates were as high as 4 million. The newly open Koh Pich was an attractive addition to the venue and promised to be a nice conclusion to the festival. I wasn’t there so I don‘t know whether the authorities posted police at the entrance to the bridge on each end to monitor the stream of people. I am sure there were at least a few as police was present in force throughout the city during the festival.

Now did the police have reason to expect or suspect that a panic might break out on the bridge in view of the masses moving over the bridge? Any clear-headed person must answer this with a ‘no’. This is just like at the end of a football/soccer game or a rock concert with 80,000 people in attendance. They may have many more exits available to leave the stadium but if people start pushing and shoving even that number of exits is not enough. It will only take a tiny spark to set off a panic and consequently a stampede. Similarly, the assumed spark that set off the stampede on that bridge could under no circumstances be expected. As a former resident of Florida, I know what it is like to be sitting on one of the many suspension bridges in your car waiting for the oncoming traffic to pass by due to a lane closure ahead. Believe me, those things do sway and shake, especially if a big truck rushes by. People just put their trust in the engineers that constructed the bridge, firm in their knowledge that those did a good job. Of course, the people here don’t know anything about that. For them the swaying was an ominous sign, which then resulted in that horrible disaster.

Finally, it appears that short of shutting those sites off for mass events there is no sure method of preventing a stampede if certain conditions prevail. Such catastrophies at one time or another strike even countries that have much more experience in crowd control than Cambodia. Perhaps one idea for the future would be to install cameras to monitor the density on the bridge, or any other public venue for mass gatherings for that matter, and once that critical density of five or six people per square meter has been reached slow down or temporarily stop the onflow or inflow of people onto the bridge or any other site for mass gatherings.