THE ORGANISATION in charge of the detailed investigation into the World Trade Center (WTC) collapses said last month that it is still awaiting key documentation for its inquiries, two years after the 11 September attacks.
Construction documents not yet received by the National Institute of Standards & Technology (NIST) include the original contract specifications for the WTC Towers, construction and maintenance logs for WTC 1, 2 and 7 and descriptions of partitions and furnishings in most of the tenant spaces of WTC 2 and 7.
'This information is vital to our inquiries. We have tried the diplomatic route so far, but people have not been willing to give it up, ' said a NIST spokesman.
He said information may be being withheld because of litigation issues, but that NIST could exercise powers given to it by the US Congress to force disclosure by subpoena.
'We will not hesitate to use the powers in our arsenal to get what we want, ' he added.
While the American Society of Civil Engineers (ASCE) produced a detailed report in May 2002 into the structural engineering aspects of the disaster (NCEI June 2002), NIST was tasked with the formal investigation and given a $16M government grant with legal powers to carry out its work.
The ASCE report set out to draw any possible early conclusions and was produced quickly by engineers working voluntarily. The NIST investigation, begun in August 2002 and due to report by September 2004, is being driven by a series of contracts awarded to experts and specialist firms who have vied for the prestigious work on the most detailed analysis ever conducted into a structural failure.
The work covers all aspects of the disasters, ranging from structural analysis and behaviour, through performance of fire protection systems, to forensic examination of materials and behaviour of occupants.
All non-technical sources are also being examined, from interviews with survivors to videos and pictures of the disaster, to enable a detailed model to replicate what happened.
'We can see from pictures what the density of smoke was and deduce the intensity of fires, for example. We have simulated fires in office environments using different quantities of jet fuel and so can match information to develop the model, ' said the spokesman.
He added that forensic investigations into the steel are near completion and showed it was of a higher grade than that required, and that steel quality is unlikely to have been a cause in the collapse.
The NIST work aims to produce a definitive technical report and model of the disaster.
A research and development programme stemming from the investigation to influence construction and structural engineering technology and the use of tall and multi-occupancy buildings in the future will follow, as well as a programme to disseminate the lessons learned.
But ASCE report chairman Gene Corley told NCEI the findings of his group remain valid.
'NIST has probably not proceeded far enough along to produce additional findings and so far there are no indications of anything different to what we had in our report. We still believe it was the fire which brought down both towers and then damaged the surrounding buildings, ' he said.
Corley said lessons learned from the disaster were already being implemented. 'I am personally aware of individual buildings - new and those which were being modified for other reasons - which have taken into account our recommendations.'
His observations have included selection of more robust fireproofing materials that can withstand higher impacts, spacing stairwells further apart and a review of fireproofing where buildings house large quantities of combustible materials.