My evidence for emergency demolition is mostly human rather than physical:
* Silverstein’s “pull it” interview,
* A news story of Silverstein desperately making ‘phone calls to arrange a demolition,
* Firefighters on video moving people away from WTC7 saying it’s about to “blow up”,
* Multiple firefighters saying that WTC7 would either fall down, or would be taken down,
* News crews and spectators seem to have been told to watch WTC7 because it would collapse,
* John Kerry said he thought so.
One non-human point:
* The necessity of removing this unstable burning building to prevent proliferation of destruction and fire; WTC7 couldn’t be permitted to topple randomly because it had other tall buildings in all directions but south, which was a rescue and recovery zone.
My precedent for emergency demolition is military demolition, performed in hours, behind enemy lines. Can it be done fast? Listen to Danny Jowenko (link), deceased Dutch demolition designer. He says that each demolition charge can be placed in minutes, and that the weeks or months of preparation are to strip the building of all hazardous materials including asbestos, arrange inspections so as to obtain a certificate, and then obtain a demolition license from the local authority.
I’d have thought New York would have been an ideal place to assemble a suitable demolition team; there’s a lot of crossover between demolition teams and military explosive handlers, and between firefighters and military lower ranks. There’s a huge naval base, and a massive population. There seem to be several demolition companies in New York.