EVACUATION DYNAMICS OF THE WORLD TRADE CENTER DISASTER

HELEN WESTENG

A project submitted in partial fulfilment of the requirements of the University of Greenwich for the degree of MSc by research

2004

ABSTRACT

The main targets with this project were to make an “easy-to-use” database containing accounts from people present in the buildings during the attacks that can be used in future research and to make a fully usable model of one of the WTC buildings.

About 250 accounts, of varied quality, were collect, analyse and catalogue in the database. The response times were extracted and used on the population in the model of WTC1. These were found to be of an average value compared to other times found in literature. Also the descent speeds were extracted and compared to the ones obtained in the computer simulations. For the average stair descent times found in this project they generally agreed to data found in the literature but they were found to be slightly lower.

There were done simulations with three main population sizes and two of them were presented in this report. These were 7 000 representing the estimated number of people in the building on the day of the attack and 25 000 representing the number of occupants on a normal working day.

For the population of 7 000 six different scenarios were run with five of them being presented in this report. For the 25 000 population seven different scenarios were run with six of them being presented here.

For the 7 000 people scenarios it could be found that the computer simulation gave results that were in comparison with documented facts. This shows that the model and population built was giving good results. For the 25 000 scenarios, population of a normal work day, it was found that not everyone would have been able to evacuate the building before it collapsed.