Keith W wrote:
[snip]
The lessons of the WTC collapse is that such truss construction
techniques should be avoided for high rise buildings, fortunately
they are not widely used which is why previous high rise
fires didnt lead to progressive collapse.
[snip]

Have you looked at the foundation of WTC 7? You wanna talk
about some lessons learned. That collection of support trusses
for a foundation was a single point failure just waiting to happen.