The November issue of JOM - Journal of the Minerals, Metals and Materials Society - features an article summarizing the results of a NIST investigation and study of the collapse of the World Trade Center Towers. The article can be found at JOM, November 2007, pp. 22-28.
The article is concerned with the metallurgical part of the collapse of the towers. NIST focused on three objectives: Quality of the steel used in construction of the towers, Determination of the mechanical properties of the steel for use in a finite element analysis of the building collapse, and an Assessment of the failure mechanisms of recovered steel components.
The article presents a thorough metallurgical analysis of the collapse, a discussion of the construction of the towers, and an analysis of the failure of the towers. The failure analysis includes a most probable collapse sequence.
NIST did the analysis at the direction of the US Congress. The article contains a number of references and can be used as a model for the analysis of a complex failure of a structure constructed of steel that is subjected to unexpected thermal loads and as well as stress.