PER-CHANDLER
David Chandler
Frame-by-frame measurements of WTC 7 roofline motion. 2011 Toronto ch.9 and 2023 journal paper with Walter and Szamboti.
Measurements are observations. Demolition inference is interpretation.
Witness statements (unmerged)
Later recollections are not folded into contemporaneous reports.
No statements stored.
Graph edges
Contradictions
Linked evidence
David Chandler — Descent and tilting of the North Tower antenna (Mar 2025)
Journal of 9/11 Studies · 2025-03-01
Chandler published a March 2025 video-measurement paper on North Tower antenna descent and tilt.
Chandler, Walter, Szamboti — Instantaneous free fall of WTC 7 and NIST's attempt to hide it (Jun 2023)
Journal of 9/11 Studies · 2023-06-01
Using multi-point tracking, Chandler/Walter/Szamboti report that after ~1.4 s of near-immobility of most of the north and west rooflines, those rooflines entered free fall together within ~0.2 s at ~8.0–8.2 s after east-penthouse collapse, ~9.8 m/s² for ~2.5 s.
David Chandler — WTC 7: A refutation of NIST's analysis (Toronto Report ch.9)
The 9/11 Toronto Report (2012), International Hearings on the Events of September 11, 2001 · 2012-09-11
Chandler's 2012 hearing paper treats NIST's own Stage 2 free-fall interval as established and argues the 5.4 s overall figure is an artefact of start-time choice.
IC911 presentations catalogue (2023–2026)
International Center for 9/11 Justice · 2026-09-02
IC911 lists seven presentations 2023–2026 on flight simulation, seismic claims, hijacking, air defence, the North Tower spire, and WTC 7 free fall.