NIST: tower collapse times ~11 s (WTC1) and ~9 s (WTC2); minimal resistance below

Observation

NIST published collapse elapsed times near free-fall order and described minimal resistance below the initiation zone.

Interpretation

Supports H003's progression-after-initiation story and is also the main official sentence that H004 cites. Ambiguous between the two until more specific column-failure evidence is weighed.

Source text

OBSERVATION: NIST FAQ and NCSTAR 1 §6.14.4 give ~11 s and ~9 s and state that the structure below offered minimal resistance.

A vacuum free-fall from ~415 m is ~9.2 s. Alternative investigators argue that a building cannot fall through itself that fast without column destruction ahead of the rubble.

NIST argues that once initiated, the falling mass so exceeded remaining capacity that resistance was negligible.

Hypothesis linkage

• H003supportsseeded

  NIST timing and 'minimal resistance' as progression after initiation.

• H004supportsseeded

  Minimal-resistance / near-free-fall times are the official sentences demolition arguments cite.