COMMITTEE
ON SCIENCE
U.S. HOUSE OF
REPRESENTATIVES
Noon to 2:00
p.m.
2318 Rayburn
House Office Building
1.
Purpose
On
Wednesday, March 6, at noon the House Committee on Science will hold a hearing
on the investigation into the collapse of the World
Trade Center (WTC).� Witnesses from
industry, academia, and government will testify on the catastrophic collapse of
the WTC complex and subsequent efforts by federal agencies and independent
researchers to understand how the building structures failed and why.� By
scrutinizing the steel and other debris, blueprints and other documents, and
recorded images of the disaster, engineers, designers, and construction
professionals may learn valuable lessons that could save thousands of lives in
the event of future catastrophes, natural or otherwise.
The Committee plans to
explore several overarching questions raised by the collapse and the ensuing
investigation:
1. What have we learned about how the federal government
investigates catastrophic building collapses, and are any changes warranted?
2. What have we learned about the collapse of the World
Trade Center, including which structural elements failed first, and why?
3.
How will we know what
changes, if any, are warranted in building and fire codes as a result of
lessons learned from the World Trade Center�s collapse?
4.
Has the World Trade
Center disaster exposed any gaps in our understanding of buildings and fire,
and are changes needed in the federal government�s research agenda?
2.
Background
At
8:47 a.m. on the morning of September 11, 2001, terrorists crashed a fuel-laden
Boeing 767 into the north tower (Tower 1) of the World Trade Center (WTC)
complex.� Approximately 16 minutes
later, a second Boeing 767 slammed into the south tower (Tower 2), exploding
upon impact and engulfing several of the building�s upper floors in
flames.� While the performance of both
towers exceeded their design specifications � the buildings were designed to
withstand the force from the initial impact of a 707 jet � the subsequent
structural and fire damage still caused the buildings to fall.� Tower 2 collapsed in less than an hour,
killing victims trapped above the flames and rescue workers in and around the
building. Thirty minutes later, Tower 1 met the same fate.� While more than 25,000 people were
successfully evacuated from the towers, nearly 3,000 people and emergency
responders were killed in the collapses.�
As the day progressed, the remaining WTC buildings collapsed as well,
including Building 7, which burned for 8 hours before crumbling to the
ground.� Fortunately, the later building
collapses produced no casualties.���
In the wake of the collapses, search and rescue
workers launched an around-the-clock recovery effort to find and recover
survivors and victims who perished.� To
make way, literally tons of twisted steel and fractured concrete were removed
from the rubble pile and loaded onto convoys of bulldozers and flatbed trucks
to be carried away to recycling plants and landfills.�
Researchers
also began to respond immediately.�
Among the first were National Science Foundation (NSF)-funded social
scientists and engineers who arrived at the WTC site within 48 to 72 hours after
the tragedy to begin collecting data.�
Similarly, the American Society of Civil Engineers (ASCE) formed a
Disaster Response Team within hours of the first plane strike.� On September 12th, the Federal
Emergency Management Agency (FEMA) and its contractor, Greenhorne and O�Mara,
Inc., located in Greenbelt, Maryland, commenced the development of a Building
Performance Assessment Team (BPAT; explained more fully on the next page) to
conduct a formal analysis of the progressive collapses and produce a report of
its findings.� A variety of other
engineering researchers and professionals, including members of the Structural
Engineering Association of New York, also engaged in the monumental task of
collecting data that could lead to a better understanding of the collapse of
the buildings themselves and to the development of mitigation strategies to
prevent a similar tragedy in the future.�
Concerns
Related to the Engineering Investigation
Though
many of the individuals who have participated in the WTC building performance
investigation are architects and engineers with experience investigating other
structural collapses � including those resulting from natural causes as well as
terrorist attacks � nothing had prepared these investigators for a disaster of this
magnitude and complexity.� Unlike the
destruction caused by an earthquake, which may affect several buildings across
an expansive area, this disaster involved many buildings and a massive debris
pile in a small, confined area.� Also
unlike most earthquakes, the WTC disaster caused significant casualties and
prompted a prolonged search and rescue effort.�
In addition, the concurrent criminal investigation by the Federal Bureau
of Investigation and a separate investigation by the National Transportation Safety
Board further frustrated the building performance investigators.��
The
investigation has been hampered by a number of issues, including:
�
No clear authority and the
absence of an effective protocol for how the building performance investigators
should conduct and coordinate their investigation with the concurrent search
and rescue efforts, as well as any criminal investigation:� Early confusion over who was in charge of
the site and the lack of authority of investigators to impound pieces of steel
for examination before they were recycled led to the loss of important pieces
of evidence that were destroyed early during the search and rescue effort.� In addition, a delay in the deployment of
FEMA�s BPAT team may have compounded the lack of access to valuable data and
artifacts.
�
Difficulty obtaining
documents essential to the investigation, including blueprints, design
drawings, and maintenance records:� The building owners, designers and insurers, prevented
independent researchers from gaining access � and delayed the BPAT team in
gaining access � to pertinent building documents largely because of liability
concerns.� The documents are necessary
to validate physical and photographic evidence and to develop computer models
that can explain why the buildings failed and how similar failures might be
avoided in the future.
�
Uncertainty as a result of
the confidential nature of the BPAT study:� The confidential nature of the BPAT study
may prevent the timely discovery of potential gaps in the investigation, which
may never be filled if important, but ephemeral evidence, such as memories or
home videotapes, are lost.� The
confidentiality agreement that FEMA requires its BPAT members to sign has
frustrated the efforts of independent researchers to understand the collapse,
who are unsure if their work is complementary to, or duplicative of, that of
the BPAT team.� In addition, the
agreement has prevented the sharing of research results and the ordinary
scientific give-and-take that otherwise allows scientists and engineers to
winnow ideas and strengthen results.�
�
Uncertainty as to the
strategy for completing the investigation and applying the lessons learned: �The BPAT team does not plan, nor does it have
sufficient funding, to fully analyze the structural data it collected to
determine the reasons for the collapse of the WTC buildings.� (Its report is expected to rely largely on
audio and video tapes of the event.)�
Nor does it plan to examine other important issues, such as building
evacuation mechanisms.� Instead, FEMA
has asked the National Institute of Standards and Technology (NIST) to take
over the investigation.� Yet so far,
NIST has not released a detailed plan describing how it will take over the
investigation, what types of analyses it will conduct, how it will attempt to
apply the lessons it learns to try to improve building and fire codes, and how
much funding it will require.����
Role of the
Federal Emergency Management Agency
The
Federal Emergency Management Agency is charged with supporting the nation�s
emergency management system.� FEMA
intervenes at all stages of disaster management including preparation,
response, recovery, mitigation, risk reduction, and prevention.� In the case of the World Trade Center
attack, FEMA dispatched Urban Search and Rescue Teams and established a
disaster field office at the site within hours of the first strike to assist in
New York City�s rescue effort.� At the
same time, the FEMA Building Performance Assessment Team (BPAT) began their
important work of initiating an analysis that could ultimately yield valuable
information about the sequence of events and failures that resulted in
progressive building collapse.
BPATs
are routinely deployed by FEMA following disasters caused by events such as
floods and hurricanes.� The teams are
formed by, and operate under the direction of the Mitigation Directorate�s
Program Assessment and Outreach Division and comprise such individuals as
regional FEMA staff, representatives from state and local governments,
consultants who are experts in engineering, design, construction, and building
codes, and other technical and support personnel.� A contractor for FEMA, Greenhorne & O�Mara, Inc., maintains a
roster of hundreds of mitigation specialists from across the United
States.� BPAT teams are typically
deployed within seven days of any disaster event.
Generally,
a BPAT conducts field inspections and technical evaluations of buildings to
identify design practices, construction methods, and building materials that
either failed or were successful in resisting the forces imposed by the
event.� A major objective of the BPAT�s
findings and recommendations are aimed at improving design, construction and
enforcement of building codes to enhance performance in future disasters.� The culmination of the BPAT�s efforts is a
report that presents the team�s observations, conclusions, and recommendations
for improving building performance in future natural disasters.
The
BPAT team deployed to the WTC site was assembled by the American Society of Civil
Engineers and is headed by W. Gene Corley, Ph.D., P.E, Senior Vice President of
Construction Technologies Laboratory in Skokie, Illinois.� He was also the principal investigator in
the FEMA study of Oklahoma City�s Murrah Federal Office Building.� On September 11th, ASCE, in
partnership with a number of other professional organizations, commenced the
formation of an independent team of experts to conduct a building performance
assessment study at the WTC site as part of ASCE�s Disaster Response Procedure.� In late September, this team, the ASCE
Disaster Response team, was officially appointed as the BPAT team and was
funded by FEMA to assess the performance of the buildings and report its
findings.� The BPAT team received
$600,000 in FEMA funding in addition to approximately $500,000 in ASCE in-kind
contributions.
The
23-member BPAT team conducted an analysis of the wreckage on-site, at Fresh
Kills Landfill and at the recycling yard from October 7-12, 2001, during which
the team extracted samples from the scrap materials and subjected them to
laboratory analysis. Why the analysis was conducted only after a delay of three
weeks after the attacks remains unclear.�
Since November, members of the Structural Engineers Association of New
York (SEAoNY) have volunteered to work on the BPAT team�s behalf and are
visiting recycling yards and landfills two to three times a week to watch for
pieces of scrap that may provide important clues with regard to the behavior of
the buildings.
In
the month that lapsed between the terrorist attacks and the deployment of the
BPAT team, a significant amount of steel debris � including most of the steel
from the upper floors � was removed from the rubble pile, cut into smaller
sections, and either melted at the recycling plant or shipped out of the
U.S.� Some of the critical pieces of
steel � including the suspension trusses from the top of the towers and the
internal support columns � were gone before the first BPAT team member ever
reached the site.� Fortunately, an
NSF-funded independent researcher, recognizing that valuable evidence was being
destroyed, attempted to intervene with the City of New York to save the
valuable artifacts, but the city was unwilling to suspend the recycling
contract.� Ultimately, the researcher
appealed directly to the recycling plant, which agreed to provide the
researcher, and ultimately the ASCE team and the SEAoNY volunteers, access to
the remaining steel and a storage area where they could temporarily store
important artifacts for additional analysis.�
Despite this agreement, however, many pieces of steel still managed to
escape inspection.
The
BPAT team is expected to release its report in April.� Because FEMA requires the members of its BPAT team to sign a
confidentiality agreement until the report is released, the exact scope of the
report is unknown.� But it appears from
the role that BPAT teams normally play and general comments ASCE members of the
BPAT team have made that the report is likely to include an examination of how
the buildings behaved leading up to the collapse, hypotheses for which
structural elements failed and thereby initiated the collapse, and
recommendations for additional research and analysis.
For
example, ASCE has said that the study will rely primarily on audio and video
recordings, interviews with survivors, blueprints and design drawings of the
World Trade Center, and evidence they or the SEAoNY volunteers have collected
from the rubble.� The BPAT team has
access to more than 120 hours of high quality film footage and audiotapes of
911 communications with trapped victims.�
The BPAT team initially had difficulty in obtaining building blueprints
and design drawings from either the City of New York, the Port Authority, the
building owners, or the building designers due primarily to liability concerns
on the part of the building owners and insurers.� Belatedly, however, the team was provided access to these
documents in early January.
ASCE
has said that the BPAT study will not include an analysis of the evacuation or
rescue procedures and may not be able to validate definitively any of a number
of hypotheses regarding the collapse.�
But because of the confidentiality of the report, it is unclear whether
the it will provide answers or simply lay out more questions.� It is unknown, for example, to what degree
the BPAT report will compare video evidence with that collected from the steel
beams from the floors that were hit by the planes.�
As
a result, independent researchers are unsure how they can contribute to the
understanding of how the buildings fell without unnecessarily duplicating
work.� Others fear that the BPAT�s
silence on the scope of its report may allow critical aspects of the picture to
be missed, and that, by the time the report is released and any such gaps are
discovered, the trail of evidence that could provide answers may have grown
cold.��
�
The
National Science Foundation
Researchers supported by the
National Science Foundation are used to mobilizing rapidly after an earthquake
and arriving on scene soon after the event to begin collecting data.� Recognizing the similarities between the WTC
disaster and earthquakes, NSF program managers awarded nearly $300,000 to
experienced earthquake researchers, including engineers and social scientists,
to begin an analysis of the 9/11 terrorist attacks within 72 hours of the
events.� In an effort to quickly deploy
researchers to the site, awards were made through the Small Grants for
Exploratory Research Program, a supplemental award program that enables NSF
program managers to award additional support to currently-funded investigators
through an abbreviated internal review process (see Appendix A for a list of
awards).�
The efforts of NSF-funded
researchers were impeded by the same obstacles the BPAT team encountered: an
inability to examine the steel, either removed from the site during the early
search and rescue work or shipped to recycling plants, and the denial of access
to building design, construction and maintenance documents.� Interestingly, it was an NSF-funded
researcher who ultimately negotiated the arrangements by which he and others
investigating the disaster were provided access to the remaining pieces of
steel at the recycling plant.�
To date, the NSF-funded
researchers continue to face problems.�
They continue to be denied access to important building diagrams and
blueprints, and so are unable to complete their analyses or develop the
computer models necessary to better understand the failure of the buildings
structural elements.� Perhaps more importantly,
without these computer models, engineering researchers will be unable to
develop effective mitigation strategies.���
The
National Institute of Standards and Technology
NISTs
Building and Fire Research Laboratory carries out research in fire science,
fire safety engineering, and structural, mechanical, and environmental
engineering.� It is the only federal
laboratory dedicated to research on building design and fire safety.� In the past, the lab has investigated
several structural failures using authority Congress made explicit in 1985. (15
U.S.C. 282a).� The goals of its previous
investigations were to determine the probable technical causes of the failures,
examine what lessons could be learned from those determinations, and help
develop improved building codes, standards, and practices.� The investigations also identified areas of
research that needed further study.
�
Shortly
after the attack, NIST appointed an employee of the Building and Fire Research
Laboratory to serve on the 23-member BPAT team.� While this partnership lent some of NIST�s resources and
expertise to the BPAT study, NIST did not immediately launch a formal
investigation into the technical causes that led to the collapse of the World Trade
Center buildings.
NIST
believes that the World Trade Center collapse raises difficult and technical
questions regarding building codes and standards, justifying the redirection of
funds to its building and fire lab.� For
example, standards for concrete design, building loads, and structural
integrity may need revision.� In
response, NIST has redirected $2 million of its fiscal year 2002 internal
discretionary funds to the lab to supplement its current building engineering
and standards work.� NIST has also
requested permission to reprogram from the rest of its laboratories another $2
million in fiscal year 2002 funds for these efforts.� The reprogramming request is currently pending before the Office
of Management and Budget and will ultimately need approval from Congress.� NIST did not need Congressional review to
redirect its discretionary funds.�
�
In
January, after a delay of three months since the terrorists� attacks, FEMA
asked NIST to take over the next phase of the investigation of the
collapse.� Yet neither NIST nor FEMA has
released details as to what that next phase would entail (other than the
general outline NIST has provided below).�
In addition, the Administration has not yet indicated whether FEMA,
NIST, or a supplemental funding request to Congress would provide funds for such
an investigation, nor has it identified how much it would cost.
Administration
officials and outside parties are weighing whether a formal arrangement should
be made for NIST to serve as FEMA�s research arm in the event of future
catastrophic building failures.�
Currently, there is no formal relationship between the two agencies
regarding these matters.
Based
on some initial planning, NIST has preliminarily identified the following
general areas for investigation:
�
Determine
technically, why and how the buildings collapsed (WTC 1 and 2, and possibly WTC
7);
�
Investigate
the technical aspects of fire protection, response, and evacuation, and
occupant behavior and response;
�
Determine
whether state-of-the-art procedures were used in the design, construction,
operation, and maintenance of the WTC building;
�
Determine
whether there are new technologies and procedures emerging that could be
employed in the future to reduce the potential risks of collapse; and
�
Identify
building and fire codes, standards, and practices that warrant revision.
3.
Questions
Please see Appendix A for copies of letters to
witnesses and the questions each was asked to address in testimony at the
hearing.
The
following witnesses will address the subcommittee:
Mr. Robert Shea, Acting Administrator Federal Insurance and Mitigation
Administration, and, Mr. Craig Wingo, Director of Division of Engineering
Science and Technology, Federal Emergency Management Administration
Dr. W. Gene Corley, P.E., S.E., American Society of Civil Engineers,
Chair of the Building Performance Assessment Team reviewing the WTC disaster
Professor Glenn Corbett, Assistant Professor of Fire
Science at John Jay College, New York City
Dr. Abolhassan Astaneh-Asl, Professor, Department of Civil and Environmental Engineering University of California, Berkeley
Dr.
Arden Bemet, Director, National Institute of Standards and Technology
5.
Additional Reading
Glanz,
J. (2001, December 4).� Wounded
Buildings Offer Survival Lessons.� The
New York Times, p. F1
Glanz,
J., & Lipton, E. (2001, December 25).�
A National Challenged: The Towers; Experts Urging Broader Inquiry in
Towers' Fall.� The New York Times,
p. A1
Glanz,
J., & Lipton, E. (2002, January 17).�
New Agency to Investigate the Collapse of Towers. �The New York Times, p. B3
Glanz, J., & Lipton, E. (2002, February 2).� At Scrapyards, as Search for Clues in the
Towers' Collapse.� The New York
Times, p. B1