Plus there is the support and endorsement of the NISTs collapse models from these guys:

http://www.asce.org/

and these guys...

http://www.aia.org/

and these guys...

http://www.ctbuh.org/

and these guys...

http://www.iccsafe.org/

and these guys...

http://www.sfpe.org/

and these guys...

http://www.nfpa.org/

and these guys...

http://www.aisc.org/

and these guys...

http://www.ncsea.com/

and these guys...

https://blume.stanford.edu/content/collapse-performance-assessment-steel-framed-buildings-under-fires

and these guys...

http://enr.construction.com/news/buildings/archives/080903.asp

and of course these guys...

http://www.nist.gov/

And then there are these guys, who did an independent second investigation for Aegis insurance on the collapse of WTC 7:

Supplemental and Amended Second Declaration of Colin G. Bailey

http://web2.westlaw.com/find/default.wl?cite=2010+WL+2019831&rs=WLW14.04&vr=2.0&rp=%2ffind%2fdefault.wl&sv=Split&fn=_top&mt=208

Supplemental and Amended Second Declaration of Guy Nordenson

http://web2.westlaw.com/find/default.wl?cite=2010+WL+2019835+&rs=WLW14.04&vr=2.0&rp=%2ffind%2fdefault.wl&sv=Split&fn=_top&mt=208

Supplemental and Amended Second Declaration of Fredrick W Mowrer - Part 1

Supplemental and Amended Second Declaration of Fredrick W Mowrer - Part 2

http://web2.westlaw.com/find/default.wl?cite=2010+WL+2019834&rs=WLW14.04&vr=2.0&rp=%2ffind%2fdefault.wl&sv=Split&fn=_top&mt=208

Supplemental and Amended Second Declaration of Joseph P. Colaco

http://web2.westlaw.com/find/default.wl?cite=2010+WL+2019832&rs=WLW14.04&vr=2.0&rp=%2ffind%2fdefault.wl&sv=Split&fn=_top&mt=208

Supplemental and Amended Declaration of Jose L. Torero

http://web2.westlaw.com/find/default.wl?cite=2010+WL+2019830&rs=WLW14.04&vr=2.0&rp=%2ffind%2fdefault.wl&sv=Split&fn=_top&mt=208