Prelude 9/11 morning Flight 11 hijacked Flight 175 hijacked WTC 1 hit Flight 77 hijacked WTC 2 hit Flight 93 hijacked Pentagon hit WTC 2 collapses Flight 93 crashes WTC 1 collapses WTC 7 collapses Epilogue

Investigation of WTC 1 and 2

NIST NCSTAR 1: Federal Building and Fire Safety Investigation of the World Trade Center Disaster: Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Tower

Full report (298 pages).

Download PDF

Download chapters

Final Reports from the NIST Investigation of the World Trade Center Disaster

Final Reports released in September 2005:

NIST NCSTAR 1: Federal Building and Fire Safety Investigation of the World Trade Center Disaster: Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Tower

NIST NCSTAR 1-1: Design, Construction, and Maintenance of Structural and Life Safety Systems

NIST NCSTAR 1-2: Baseline Structural Performance and Aircraft Impact Damage Analysis of the World Trade Center Towers

NIST NCSTAR 1-3: Mechanical and Metallurgical Analysis of Structural Steel

NIST NCSTAR 1-4: Active Fire Protection Systems

NIST NCSTAR 1-5: Reconstruction of the Fires in the World Trade Center Towers

NIST NCSTAR 1-6: Structural Fire Response and Probable Collapse Sequence of the World Trade Center Towers

NIST NCSTAR 1-7: Occupant Behavior, Egress, and Emergency Communication

NIST NCSTAR 1-8: The Emergency Response Operations