Originally Posted by Mutton-Head
What is your point?
In the history of buildings, only a fraction of a fraction are what could be called 'high-rise'.
Of them, only a fraction would be considered 'steel structures' (a term you had best look at more carefully, BTW. Many, if not most high rise buildings use concrete cores).
Of them only a fraction of a fraction have ever been in danger of any sort (bombings, fire, earthquakes).
Of them, only a small portion received damage that could result in pancake collapse, which requires fire or other cricumstances to fail the building at a point other than its base. The count of how many outside the WTC attacks that reached this level of danger could be counted on one deformed hand.
Of them, most were damaged beyond repair or at least partially collapsed.
Of them, only the WTC buildings have collapsed completely.
Your complaint seems to be that we must find prior examples from a sample pool that is extremely small to begin with.
Structural Engineers, and many other types of Engineers understand completely how pancake collapse can occour. You are saying these experts, who design buildings that people work and live in, do not understand what they are talking about. We are simply supposed to take your word for it.