'The WTC, on this low-wind day, was likely not stressed more than
a third of the design allowable, which is roughly one-fifth of the yield
strength of the steel. Even with its strength halved, the steel could still
support two to three times the stresses imposed by a 650°C fire.'
http://www.tms.org/pubs/journals/JOM...agar-0112.html
So what went wrong, 'chico'? Tell us how you think it happened.
WELL?