 But because nano-thermites are created from reactant particles with proximities approaching the atomic scale, energy release rates are far improved.The NIST report provides an analysis of the structural response of the building only up to the point where collapse begins, and asserts that the enormous kinetic energy transferred by the falling part of the building makes progressive collapse inevitable once an initial collapse occurs.A paper by Zdeněk Bažant indicates that once collapse began, the kinetic energy imparted by a falling upper section onto the floor below was an order of magnitude greater than that which the lower section could support.