Crucially, the building remained standing despite the intensity
of the fire. An investigation is underway between Spanish technical
agency Intemac and UK authorities including Arup Fire, the
University of Edinburgh and the concrete industry including
Cembureau, BCA and The Concrete Centre. Preliminary findings
suggest that a combination of the upper technical floor and the
excellent passive fire resistance of the tower's concrete columns
and core prevented total building collapse.
The fire is significant in terms of its potential similarities
between the collapse of the building's steel frame above the 17th
floor and the experience seen at the World Trade Center. Notably,
one of the recommendations of NIST's interim report on the World
Trade Center disaster is for tall building design to incorporate
'strong points' within the frame.