February 6, 2006
Scientists group AGHAM say Wowowee tragedy a disaster waiting to happen: Narrow exits, lack of coordination and the push of poverty contributed to the stampede
"Narrow exits, lack of coordination, absence of exit plans, movement in multiple directions combined with a strong desire to reach an objective due to poverty is a recipe for panic-induced stampede", said Dr. Giovanni Tapang, chairperson of the activist scientist group AGHAM or the Samahan ng Nagtataguyod ng Agham at Teknolohiya para sa Sambayanan and coauthor of several papers on panic exit dynamics at the National Institute of Physics at the UP Diliman.
Tapang related the results of a study done with project leader Dr. Caesar Saloma, Gay Perez, Dr. May Lim and Dr. Cynthia Palmes-Saloma that were published in scientific journals Physica A and the Proceedings of the National Academy of Sciences USA in 2002 and 2003. The study done at the University of the Philippines demonstrated in simulation and actual experiments with mice that several factors can trigger panic-induced clogging at exits or passageways.
One factor is the width and design of the passageway. A narrow exit leads to collective slow-down that emerges among pedestrians crossing in each other's path. This slowdown (or jamming) reduces the number of people who can exit.
"This disruptive interference of paths can be minimized if you have guided railings near the entrances or entryways positioned far enough from each other. Such design was lacking in the Wowowee anniversary at the ULTRA", Dr. Tapang explained.
In their simulation and experiment, another factor was that exiting agents would tend to follow their nearest neighbor if they are not provided with a clear exit plan.
"In the Wowowee tragedy, the people gathering there apparently were not given a clear plan on how to enter or exit the ULTRA thus contributing to rapid clogging at the gate. The number of people is important although a panic-induced stampede can occur even in rooms with 30 people in it given the right conditions", the AGHAM chairperson added.
The biggest factor is the amount of panic or the drive to reach the exit. The study has shown that increasing the "panic parameter" decreases the number of those who can pass through the passageway: the higher the drive to reach the exit, the lower the throughput you will
Tapang said that it is obvious that those who came to Wowowee was hoping to get big cash prizes up at stake in the show at this time of high unemployment, sinking wages and rising costs of commodities, rates, and services due to the RVAT and oil price hikes. "This push of poverty was the final element in the recipe leading to the tragedy", underscored Dr. Tapang.
"It could have been avoided if there was good planning and coordination and if there were none of the desperation of the people due to the hard times nowadays", concluded Dr. Tapang.###
1. Streaming, disruptive interference and power-law behavior in the exit dynamics of confned pedestrians, Gay Jane Perez, Giovanni Tapang, May Lim, Caesar Saloma Physica A 312 (2002) 609 – 618
2. Self-organized queuing and scale-free behavior in real escape panic, Caesar Saloma, Gay Jane Perez, Giovanni Tapang, May Lim, and Cynthia Palmes-Saloma, PNAS USA, Vol. 100, pp. 11947-11952 (2003)
A disaster waiting to happen: Narrow exits, lack of coordination and the push of poverty contributed to the Wowowee stampede
February 6, 2006
posted: ganni @ 6.2.06