Following the WTC disaster, the
Building Disaster Assessment Group (BDAG) of the UK Office of the Deputy
Prime Minister, funded the Fire Safety Engineering Group (FSEG) of the
University of Greenwich to gather, collate, categorise, electronically store and
finally analyse data concerning human behaviour during the WTC evacuation.
Two types of material were collected and analysed, the results for which are
presented in two separate reports.
REPORT 1: Collection and Analysis of Human Behaviour Data
appearing in the mass media relating to the evacuation of The World Trade Centre
Towers of 11 September 2001.
REPORT 2: Collection and Analysis of Emergency Services Data Relating to the
Evacuation of the World Trade Centre Towers of 11 September 2001.
REPORT 1 Overview:
Evacuation accounts were gathered from the
literature published in the public domain. Material sources ranged from survivor
accounts printed in newspapers and newspaper web sites, interviews in the
electronic media, survivor web sites and books. Over 250 separate accounts were
gathered that described occupant behaviour. Information appearing in print
newspapers represents 70% of the accounts while information from websites (news
and personal) represents 16% of the accounts. The remainder of the accounts have
appeared in books, journals and the electronic media. These accounts provided
information concerning 120 people from WTC1 (north tower or WTC1) and 119 from
WTC2 (south tower or WTC2) and 21 of unknown origin.
The collected
accounts were entered into a specially developed database. The database itself
was designed to be a flexible qualitative research tool enabling the
categorisation of occupants’ experiences during the data input process. As part
of the data entry, the entire verbatim data account was stored. In addition,
each individual experience described within the account were stored and assigned
specific behavioural references. This is similar to traditional qualitative
analysis tools that allow users to categorise portions of textual accounts
during the input process. The database contains reference to a total of 3291
experiences from 260 people (1869 accounts from WTC1, 1411 from WTC2 and 11 from
unknown locations).
In reviewing the findings of this report, it must be
remembered that the data on which the analysis is based was not collected in a
scientific manner but from accounts in the public domain, primarily press
accounts. As such it is difficult to generalise many of the findings. However,
as much of the data was reported days after the incident, it provides a unique
and insightful glimpse into the human response to such emergencies. The key
findings of this research may be found in Report 1. The results are presented
under the following headings:
Of the 115 people who provided information on which a pre-evacuation time could be estimated, 60% responded within an estimated 5 minutes of the assault on WTC1 and some 13% took longer than an estimated 17 minutes to respond. Occupants in WTC2 responded quicker to the assault than occupants in WTC1 - the first tower to be attacked. This occurred in WTC2 despite instructions issued over the PA system in WTC2 instructing occupants that there was no need to evacuate WTC2.
(i) State of mind.
(ii) Nature of pre-evacuation actions.
(iii)
Knowledge of the event:
(iv) Usage of telephones:
(v) Collecting Items:
(i) Flow conditions within the towers
(ii) Obstructions to flow
(iii) Usage of elevators as a means of evacuation in WTC2
(iv) Group
Behaviour
(v) Stair Travel Speeds
(vi) Fire Wardens
(vii) Fatigue
This study has provided insight into the response of people
subjected to extreme emergency conditions in high rise buildings. The
information is useful in its own right in understanding how the evacuation of
the World Trade Centre Towers evolved on 11 September 2001. More significantly,
the insight gained will be useful in shaping our building codes and devising
emergency procedures for evacuation. Furthermore, the information collected will
be invaluable in assisting the development of behaviour models that are key
components of evacuation models used in performance based building design and in
providing data for model scenario specification.
The data collected and
analysed in this study will be used as the starting point for a much larger
project into the evacuation of the WTC. The project, called HEED – High-rise
Evacuation Evaluation Database – funded by the UK EPSRC (project GR/S74201/01)
and involving the Universities of Greenwich, Ulster and Liverpool, aims to
interview 2000 survivors of the WTC twin towers evacuation.
Download Report 1: PDF 1.86 MB
REPORT 2 Overview:
Towards the end of 2003, FSEG obtained six
PDF documents comprising approximately 5,000 pages of data relating to the WTC
evacuation. This information consisted of:
- Four PDF documents of telephone and radio calls and conversations which occurred on the 11 September 2001 between New York and New Jersey Police agencies and callers.
- Two PDF documents comprised letters of commendation for individual Police Officers and an account of the incident by the Officer concerned.
BDAG requested that FSEG should enter this information into the database and
analyse the information. The report focuses on the effectiveness of the
emergency response and attempts to identify issues which might help future
planning. The key findings of this research may be found in Report 2. The
results are presented under the following headings:
(i) Recognition of
the situation
(ii) Police logistical and tactical response
(iii)
Evacuation of tower concourses
(iv) Police ascent of towers
(v) Emergency
Equipment
(vi) Command Posts
(vii) Communications
(viii) Decision to evacuate the towers
(ix)
Trapped occupants
(x) Locked exit routes
(xi) Telephone calls by and to
the Police
This study has provided insight into the response of the rescue services
operating under extreme emergency conditions in high rise buildings. The
information is useful in its own right in understanding how the emergency
services responded to the World Trade Centre disaster of 11 September 2001. More
significantly, the insight gained will be useful in shaping our emergency
procedures for evacuation.
Download
Report 2: PDF 355 KB
Reference:
Collection and Analysis
of Human Behaviour Data appearing in the mass media relating to the evacuation
of the World Trade Centre Towers of 11 September 2001, Galea E.R and Blake S.,
University of Greenwich Fire Safety Engineering Group. A report prepared for the
Building Disaster Assessment Group of the UK Office of the Deputy Prime
Minister. 30/07/04.
Collection and Analysis of Emergency Services data
relating to the evacuation of the World Trade Centre Towers of 11 September
2001, Galea E.R and Dixon A., University of Greenwich Fire Safety Engineering
Group. A report prepared for the Building Disaster Assessment Group of the UK
Office of the Deputy Prime Minister. 31/07/04.
See
publications #162, 95