What Nigro and Cassano described
Daniel Nigro, chief of operations on 9/11, described heavy fire at WTC 7, reported structural damage, then suspended operations and set a collapse zone about two or three blocks in each direction in a Firehouse Magazine interview published June 1, 2002 (interview date unstated). Sal Cassano, citywide tour commander that day, gave the collapse time as about 5:30. [1]
The withdrawal decision and collapse zone
In a task-force interview on October 24, 2001, Nigro described damage and fires at 7 World Trade Center, reported an assessment of its condition, ordered evacuation of a surrounding area, gave up some rescue work and continued operations at a distance. The New York Times-hosted transcript identifies James Drury as the interviewer. His times for events and the collapse are approximate; the account is retrospective, describing assessments and decisions. The published transcript has transcription and ordering defects. Because it is another interview with Nigro, it does not add independent corroboration. The passage gives no dimensions for the evacuated area. [3]
Reported times and their limits
NIST reports the collapse at 5:20:52 p.m. on September 11, 2001, after fires burned for almost seven hours from the 10:28:22 a.m. collapse of the north tower. Its WTC 7 FAQ also says the decision to stop trying to save the building came nearly three hours before it fell. The FAQ text does not state a time zone. As a later investigation summary, not a dispatch log, the FAQ supplies a precise figure without reconciling the witness accounts. [2]
BBC's WTC 7 timeline, updated October 17, 2008, places Nigro's decision to establish an evacuation zone and stop rescue work within that zone at approximately 15:00. The entry comes from a later chronology; it supplies neither an exact decision time nor a new witness. [4]