From the NIST Final Reports of the Federal Building and Fire Investigation of the World Trade Center Disaster:
OOPS! This is a report years in the making, and the bolded part is in direct contradiction to what FEMA's WTC Steel Data Collection report found:
and from FEMA's Limited Metallurgical Examination:
and from An Initial Microstructural Analysis of A36 Steel from WTC Building 7:
So the steel from wtc7 also falls into the memory hole. Oh well, just more paranoia I guess. :laugh:
The analysis focused on the WTC 1 and WTC 2. Although no steel was recovered from WTC 7, a 47-story building that also collapsed on September 11, properties for steel used in its construction were estimated based on literature and contemporaneous documents.
OOPS! This is a report years in the making, and the bolded part is in direct contradiction to what FEMA's WTC Steel Data Collection report found:
WTC steel data collection efforts were undertaken by the Building Performance Study (BPS) Team and the Structural Engineers Association of New York (SEAoNY) to identify significant steel pieces from WTC 1, 2, 5, and 7 for further study
and from FEMA's Limited Metallurgical Examination:
Two structural steel members with unusual erosion patterns were observed in the WTC debris field. The first appeared to be from WTC 7 and the second from either WTC 1 or WTC 2. Samples were taken from these beams and labelled Sample 1 and sample 2, respectively. A mettallurgical examination was conducted.
C.2 Sample 1 (from WTC 7) Several regions in the section of the beam shown in Figures C-1 and C-2 were examined to determine microstructural changes that occured in the A36 structural steel as a result of the events of September 11, 2001, and the subsequent fires. Although the exact location of this beam in the building was not known, the severe erosion found in several beams warranted further consideration.
and from An Initial Microstructural Analysis of A36 Steel from WTC Building 7:
section of an A36 wide flange beam retrieved from the collapsed World Trade Center Building 7 was examined to determine changes in the steel microstructure as a result of the terrorist attack on September 11, 2001
So the steel from wtc7 also falls into the memory hole. Oh well, just more paranoia I guess. :laugh: