September 13, 2023
NIST Update on Champlain Towers Collapse Investigation
Overview
The NCST also reported progress in building a computer
model to simulate the collapse initiation and progression.
On June 24, 2021, part of the Champlain Towers South, a
12-story residential building, collapsed in Surfside, FL,
In addition, the NCST team is actively seeking additional
killing 98 people. On June 25, the National Institute of
photos or videos of the building during the collapse to aid
Standards and Technology (NIST) National Construction
in its analysis.
Safety Team (NCST) sent investigators to the site to
identify factors contributing to the collapse. On June 30,
NIST anticipates that the NCST will complete its technical
NIST launched a full technical investigation of the collapse.
work in June 2024 with release of its final report, including
findings and recommendations, in June 2025.
Still underway, the NCST investigation is exploring a
number of factors that might have contributed to the
NIST, NCST Authorities Under the
collapse, including sinkholes, excessive settling of the
National Construction Safety Team Act
building’s pile foundations, and other factors.
Congress enacted the National Construction Safety Team
On September 7, 2023, the NCST reported on the
(NCST) Act (P.L. 107-231) in October 2002 authorizing the
investigation’s findings to date. The update included
NIST, a non-regulatory agency of the Department of
preliminary evaluations of the data collected on site
Commerce, to establish teams to investigate building
conditions and deviations from design in the construction of
failures. NCST Act authorities are similar to those of the
the building’s pool deck.
National Transportation Safety
Board
(NTSB
), the federal
agency that investigates transportation accidents.
Preliminary Findings
Under the act, the NCST is charged with “improv[ing] the
According to NIST,
safety and structural integrity of buildings in the United
The [NCST’s] preliminary evaluation of the data
States” by providing “for the establishment of investigative
collected indicates that approximately one quarter
teams to assess building performance and emergency
of an inch or less of settling occurred in the pile
response and evacuation procedures in the wake of any
foundations supporting the pool deck structure and
building failure that has resulted in substantial loss of life or
that posed the potential for substantial loss of life.”
basement, which would have had minimal impact
on the pool deck structure. The preliminary
The NCST Act authorizes NIST to dispatch teams of
evaluation did not reveal evidence of sinkholes that
experts, where appropriate and practical, within 48 hours
could have created voids under the foundation.
after major building disasters. Each team must have at least
The team’s preliminary evaluation of physical and
one NIST employee. Teams may include private sector and
historical evidence also revealed how the
university experts, representatives of professional
construction of the pool deck deviated from design
organizations, and appropriate federal, state, and local
requirements. This adds to the low margins against
officials. Under the act, NSCT teams are to:
failure that were [previously identified].
• establish the likely technical cause or causes of
Specifically, the team found that the number of slab
building failures;
reinforcing bars centered over vertical columns was
• evaluate the technical aspects of evacuation and
inadequate and that the reinforcing bars in the top
emergency response procedures;
of the slab in the vicinity of the columns were
•
spaced farther apart than the design required. These
recommend, as necessary, specific improvements to
building standards, codes, and practices;
deviations weakened the slab-column connections.
•
In the course of its investigation, the NCST has extracted
recommend any research and other appropriate actions
needed to improve the structural safety of buildings,
more than 300 concrete cores and rebar samples from the
and to improve evacuation and emergency response
site and begun materials testing. Thus far, according to the
NCST, “the average tested concrete strength for various
procedures; and
types of structural elements such as slabs and columns
• within 90 days of completing an investigation, issue a
exceeds the specified design strength for those elements.”
public report of findings and recommendations.
The NCST Act authorizes NIST and its investigative teams
to access the site of a building disaster; subpoena evidence;
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NIST Update on Champlain Towers Collapse Investigation
access key pieces of evidence, such as records and
NIST and Building Codes, Standards, and
documents; and move and preserve evidence. Under the act,
Practices
NIST may not interfere with active search, rescue, or
NIST is not a regulatory agency; it does not determine
recovery operations at the failure site. In addition, NIST
which building and fire safety codes, standards, and
investigative authorities are secondary to any criminal or
practices get adopted by state and local governments. In
terrorist investigation.
particular, the NCST Act specifically states that it does not
confer any authority on NIST to require the adoption of
NIST does not consider findings of fault, responsibility, or
building codes, standards, or practices.
negligence. No part of any report resulting from an NCST
investigation may be admitted as evidence or used in any
NIST does support the development of building codes and
suit or action for damages arising out of any matter
standards in a variety of ways, however. For example, NIST
mentioned in such report.
research supports the development of codes and standards,
including measures of building resilience and structural
Under the act, NIST is to brief the public regularly on the
robustness related to disasters, such as hurricanes,
status of investigative proceedings and findings.
earthquakes, tornadoes, and blast and impact events; hazard
characterization and structural design; materials research;
The act also authorizes the Director of NIST to establish a
understanding fire behavior and structural response to fire;
standing NCST Advisory Committee of up to 10 persons
and construction and in-service failures.
with broad technical expertise and experience to provide
advice. Each year, the advisory committee is to transmit a
In particular, the NIST Engineering Laboratory’s Materials
report to Congress that includes an evaluation of NCST Act
and Structural Systems Division develops and promotes the
activities, recommendations to improve the operation and
use of science-based tools—including measurements, data,
effectiveness of investigation teams, and an assessment of
models, protocols, and reference standards—to improve the
the implementation of team and advisory committee
global competitiveness of U.S. industry through innovations
recommendations.
in building materials and construction technology, and to
Decision to Conduct an NCST
improve the safety, security, and sustainability of the
Investigation
nation’s buildings and physical infrastructure.
According to NIST, before deciding whether to conduct a
The laboratory’s work aims to address a gap between basic
full NSTC technical investigation, NIST sends experts to
research and building codes, standards, and practices
the site of the building failure to collect initial information
through measurement science research. This research is
about the event. The NIST Director may order a full NCST
intended to contribute to the development and improvement
Act technical investigation after ensuring that the event is
of standards and building codes.
within the jurisdiction of the National Construction Safety
Team Act, and that the building material and construction
Options for Congress
type exist broadly in a region or across the country.
Previous NSTC Act investigations have taken two years or
Given public concerns that the conditions leading to the
more to complete.
collapse of the Champlain Towers South building might be
present in other buildings, Congress might consider whether
Prior and Current NIST NCST
to hold public hearings on the results of the investigation
Investigations
thus far, and implications, if any, for existing buildings and
the design, construction, and regulation of future buildings.
NIST has completed three NCST Act investigations:
• World Trade Center (WTC) collapses (final report on
Relevant Statutes
the collapse of the Twin Towers issued in 2005, final
15 U.S.C. §§7301 et seq.—National Construction Safety
report on collapse of WTC 7 building issued in 2008);
Teams
• Station Nightclub Fire in West Warwick, RI (final
15 U.S.C. §281a—Structural failures
report issued in 2005); and
• Joplin, MO, Tornado in May 2011, the single deadliest
Other Resources
and costliest tornado in U.S. history (final report issued
NIST Building Codes and Standards
in 2014).
NIST Construction and In-Service Failure
NIST is currently conducting an NCST Act investigation of
NIST Materials and Structural Systems Division
the effects of Hurricane Maria on Puerto Rico in September
NIST National Fire Research Laboratory
2017. NIST issued a progress report in January 2021. The
draft final report for public comment on the Hurricane
NCST Advisory Committee
Maria investigation is expected in 2025.
John F. Sargent Jr., Specialist in Science and Technology
Policy
IF12496
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NIST Update on Champlain Towers Collapse Investigation
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