NCST Investigation of the 

Champlain Towers Collapse

Investigation Update

Glenn Bell

Associate Lead Investigator

Source: NIST 1
CT NCST Investigation Update: Agenda

1. Investigation objectives

2. Investigative approach and flow

3. Recent accomplishments

4. Project plans

5. Project management and budget

6. Next steps
CT NCST Investigation Update: Investigative Objectives

National Construction Safety Team Act

Technical Cause(s) + Recommendations
CT NCST Investigation Update: Investigative Approach and Flow

1. Investigation objectives

2. Investigative approach and flow

3. Recent accomplishments

4. Project plans

5. Project management and budget

6. Next steps
CT NCST Investigation Update: Failure Cause(s)

Analysis of Failure Data

1. Videos of failure

2. Eyewitness accounts

3. Analysis of debris pile (photos, scans, videos, 

etc.)

4. Observation of individual pieces of physical 

evidence

Analysis of Demand and 

Capacity

1. Initiation of failure (demand exceeds capacity)

2. Progression of failure (progressive collapse 

analysis)

seek a match

Analysis of Capacity: What were the 

ultimate strengths of elements of the 

structure and structure as a whole at 

the time of failure?

• Original design

• Original construction (configuration, details, 

materials)

• Modifications made over time

• Deterioration

• Material (concrete and steel)

• Fatigue 

• Soil conditions and foundation 

settlements

• Previous loadings

Analysis of Demand: What loads 

and environmental conditions were 

acting on the structure at the time of 

failure?

• Dead

• Live

• Wind

• Thermal and shrinkage

• Extraordinary conditions (e.g., blast, 

vehicle impact, flooding)

• Vibrations
CT NCST Investigation Update : Development and 

Analysis of Failure Hypotheses

Develop and analyze failure hypotheses

5. Geotechnical Engineering 

• Soil

• Foundations

• Groundwater

1. Building and code history

• Building code history

• Design 

• Construction

• Modifications

• Load and environmental history

• Repairs and maintenance

• Deterioration

3. Remote sensing

• Lidar

• Drone

• Time-lapse photography

• Groundwater monitoring

2. Evidence preservation 

• Documents

• Eyewitness accounts

• Specimens

• Photos, videos, scans by others

6. Structural Engineering

• Code compliance

• Failure initiation

• Failure progression

4. Material science

• Concrete

• Steel reinforcing

• Degradation mechanisms

Institutional Support and Data Management Analysis of failure data

+
CT NCST Investigation Update

1. Investigation objectives

2. Investigative approach and flow

3. Recent accomplishments

4. Project plans

5. Project management and budget

6. Next steps
CT NCST Investigation Update: Recent Accomplishments

❑ Physical evidence

❑ Data processing, curation, IT infrastructure

❑ Recruiting/onboarding project teams

❑ Develop failure hypotheses

❑ Geotechnical laboratory work

❑ Structural modeling

❑ Codes, standards, reference docs

❑ Interviews

❑ Project planning

Source: NIST
CT NCST Investigation Update: Recent Accomplishments

❑ Physical evidence

❑ Data processing, curation, IT infrastructure

❑ Recruiting/onboarding project teams

❑ Develop failure hypotheses

❑ Geotechnical laboratory work

❑ Structural modeling

❑ Codes, standards, reference docs

❑ Interviews

❑ Project planning

NIST CTS Database

CTS NCST 

workspace

Site 

information 

from internal 

NIST sources

Site 

information 

from external 

NIST sources
CT NCST Investigation Update: Recent Accomplishments

❑ Physical evidence

❑ Data processing, curation, IT infrastructure

❑ Recruiting/onboarding project teams

❑ Develop failure hypotheses

❑ Geotechnical laboratory work

❑ Structural modeling

❑ Codes, standards, reference docs

❑ Interviews

❑ Project planning
CT NCST Investigation Update: Recent Accomplishments

❑ Physical evidence

❑ Data processing, curation, IT infrastructure

❑ Recruiting/onboarding project teams

❑ Develop failure hypotheses

❑ Geotechnical laboratory work

❑ Structural modeling

❑ Codes, standards, reference docs

❑ Interviews

❑ Project planning
CT NCST Investigation Update: Recent Accomplishments

❑ Physical evidence

❑ Data processing, curation, IT infrastructure

❑ Recruiting/onboarding project teams

❑ Develop failure hypotheses

❑ Geotechnical laboratory work

❑ Structural modeling

❑ Codes, standards, reference docs

❑ Interviews

❑ Project planning

Source: NIST
CT NCST Investigation Update: Recent Accomplishments

❑ Physical evidence

❑ Data processing, curation, IT infrastructure

❑ Recruiting/onboarding project teams

❑ Develop failure hypotheses

❑ Geotechnical laboratory work

❑ Structural modeling

❑ Codes, standards, reference docs

❑ Interviews

❑ Project planning

Source: NIST, using ETABS® software
CT NCST Investigation Update: Recent Accomplishments

❑ Physical evidence

❑ Data processing, curation, IT infrastructure

❑ Recruiting/onboarding project teams

❑ Develop failure hypotheses

❑ Geotechnical laboratory work

❑ Structural modeling

❑ Codes, standards, reference docs

❑ Interviews

❑ Project planning
CT NCST Investigation Update: Recent Accomplishments

❑ Physical evidence

❑ Data processing, curation, IT infrastructure

❑ Recruiting/onboarding project teams

❑ Develop failure hypotheses

❑ Geotechnical laboratory work

❑ Structural modeling

❑ Codes, standards, reference docs

❑ Interviews

❑ Project planning

Source: NIST
CT NCST Investigation Update: Recent Accomplishments

❑ Physical evidence

❑ Data processing, curation, IT infrastructure

❑ Recruiting/onboarding project teams

❑ Develop failure hypotheses

❑ Geotechnical laboratory work

❑ Structural modeling

❑ External data collection

❑ Interviews

❑ Project planning
Champlain Towers South Collapse: History

Building and Code History

The objective of this project is to assess the entire history 

of the building from original design through the partial 

collapse, including relevant codes and standards, design 

drawings and other documents, construction records, 

inspections, maintenance, renovations, and loads and 

environmental conditions.
Champlain Towers South Collapse: History

Source: Glenn Bell Source: Google Earth

Data: SIO, U.S. Navy, NGA, GEBCO

Next steps

❖ Continue reviewing and summarize currently 

available documentation for design, construction, 

and maintenance/repairs/renovations of CTS

❖ Continue interviewing people with historic 

knowledge of construction in the South Florida 

area

Principal project tasks

❖ Study site history, design and construction 

considerations to establish the as-built condition of 

CTS

❖ Determine what maintenance, repairs and 

renovations occurred over the life of the structure

❖ Study the history of site, loading, and 

environmental conditions affecting the condition of 

CTS
Champlain Towers South Collapse: Evidence Preservation

Evidence Preservation

The objective of this project is to use innovative tagging 

and data collection methods to catalog and organize 

evidence and ensure the integrity of its origin through 

proper storage, handling and sampling. This project will 

also include interviews of residents, first responders, 

family members or others with knowledge of the building 

condition and collapse events.
Champlain Towers South Collapse: Evidence Preservation

Next steps

❖ Determine original locations of specimens in 

CTS

❖ Develop protocols for detailed documentation 

of the specimens

Principal project tasks

❖ Create an evidence database to catalog and 

classify physical specimens from CTS 

❖ Store, manage, and preserve physical 

specimens. Manage the process of 

subsample collection and destructive testing

❖ Collect and analyze non-physical evidence

Source: NIST
Champlain Towers South Collapse: Sensing & Visualization

Remote Sensing & Visualization

The objective of this project is to provide a 

comprehensive 3D geospatial data management solution 

to compile, organize, visualize, and communicate the 

surface and subsurface data from the Champlain Towers 

South building collapse investigation. 
Champlain Towers South Collapse: Sensing & Visualization

Next steps

❖ Establish desired data structure based on 

needs of project teams

❖ Create building information model and begin to 

populate database

Principal project tasks

❖ Create a three-dimensional model of CTS 

including the superstructure, foundation and 

geotechnical conditions, and relevant features 

of surrounding site

❖ Work with project teams to define nature and 

sources of data to be contained in the building 

information model

❖ Provide project teams with a comprehensive 

3D geospatial data management solution

Source: NIST, using ETABS® software
Champlain Towers South Collapse: Material Science

Materials Science

The objective of this project is to evaluate materials used 

in specific building features and at different locations in 

the building for their initial mechanical properties and 

durability and how those properties may have changed 

over time as a result of service, exposure, maintenance, 

and repair. This project will compare these to design 

specifications and guidelines for monitoring, maintenance, 

and repair. Data will be used in analyses and simulations 

of the partial collapse.
Champlain Towers South Collapse: Material Science

Next steps

❖ Continue NDT on specimens 

❖ Develop initial sampling and destructive testing 

plan for material subsamples

Principal project tasks

❖ Use material-level NDT to rapidly characterize 

properties of building debris

❖ Conduct a comprehensive program of 

subsample testing (microscopic to mechanical) 

to characterize relevant structural elements, 

including concrete and steel reinforcing 

components

❖ Identify concrete and steel degradation 

mechanisms
Champlain Towers South Collapse: Geotechnical Engineering

Geotechnical Engineering 

The objective of this project is to evaluate the 

foundation’s design, its as-built construction and its 

current condition. It will also assess geotechnical and soil 

factors that may have affected the foundation.
Next steps

❖ Process data collected in site investigation

❖ Complete laboratory testing of specimens 

retrieved from site

Principal project tasks

❖ Characterize the site history and geologic 

development

❖ Conduct a comprehensive subsurface 

investigation. Determine properties of the 

subsurface materials and foundations

❖ Analyze and evaluate the subsurface and 

substructure performance

Source: NIST

Champlain Towers South Collapse: Geotechnical Engineering
Champlain Towers South Collapse: Structural Engineering

Structural Engineering

The objective of this project is to use evidence collected 

from the collapse site, the results of the other projects, 

and structural engineering and reinforced concrete design 

knowledge to generate computer models that will simulate 

the failure initiation and progression.
Champlain Towers South Collapse: Structural Engineering

Next steps

❖ Complete baseline analysis to assess design 

of structure under design gravity and wind 

loading

❖ Develop laboratory testing program

Source: NIST, using ETABS® software

Principal project tasks

❖ Develop validated models of building structure 

and components to understand performance 

characteristics and use in global collapse 

analysis

❖ Conduct testing of selected building 

components to understand performance 

characteristics and use in global collapse 

analysis

❖ Simulate global collapse of the structure
CT NCST Investigation Update

1. Investigation objectives

2. Investigative approach and flow

3. Recent accomplishments

4. Project plans

5. Project management and budget

6. Next steps
CT NCST Investigation Update: Project Management

1. Individual project teams meet weekly

2. Collective project teams meet weekly, 

alternating team leadership only and 

full team membership

3. Lead investigator and Associate Lead 

Investigator meet weekly

4. Investigation leaders meet with DFS 

Director and Division and 

Engineering lab leadership 

approximately biweekly
CT NCST Investigation Update: Project Budget

H.R. 5305, Division B
CT NCST Investigation Update

1. Investigation objectives

2. Investigative approach and flow

3. Recent accomplishments

4. Project plans

5. Project management and budget

6. Next Steps
CT NCST Investigation Update: Next Steps

• Protocols for evidence management and sharing

• Process field data collected through site work 

• Refine project plan and budget

• Round out project team members and onboarding

• Eyewitness accounts

• Acquire external information: documents, photos, videos

DISCLAIMER Certain commercial software, equipment, instruments, or materials may have been used in the preparation of information 

contributing to this presentation. Identification in this paper is not intended to imply recommendation or endorsement by NIST, nor is it intended to 

imply that such software, equipment, instruments, or materials are necessarily the best available for the purpose.
Thank you

Glenn R. Bell

glenn.bell@nist.gov

Associate Lead Investigator, Champlain Towers NCST Investigation

National Institute of Standards and Technology

U.S. Department of Commerce