The discussion on structural robustness rightly continues, highlighted by the ASCE/FEMA report and enlivened by contributions from those with allegiances to particular materials. Martin Southcott (NCE 6 June) says that concrete frames are inherently safe and robust.
I would qualify this by noting that concrete structures can be robust when sufficient connectivity is achieved between the elements of the structure.
Ronan Point, for example, was built of concrete but was hardly robust. The way that we as engineers use the materials available to us is as important as their inherent properties.
David Hadden (M), associate director, Arup Security Consulting, 13 Fitzroy Street, London, W1T 4BQ