Other than with speculative theories which are not supported by the majority of the engineering community (see Partin Report), it has been widely accepted that the trigger to the collapse of the Murrah Federal Building was the detonation of a homemade bomb contained in a rental truck which was parked in front of the nine-story office building on N.W. Fifth Street. The resulting crater from the blast was approximately 28 feet in diameter and 7 feet deep. This crater was measured to be only about 10 feet away from Column G20 of the Murrah Building. After conducting analysis, the BPAT found that the required energy which would result in a crater of equal magnitude would be equivalent to that of the detonation of approximately 4,000 lbs of trinitrotoluene (TNT) (Mlakar, 1998, p. 113). After additional investigation, it was determined that the rental truck had been loaded with an estimated 4,800 lbs of ammonium nitrate and fuel oil explosive, also known as ANFO (Delatte, 2009, p.157). The detonation of bomb of this magnitude produces a radially propagating air-blast wave. The BPAT calculated that resulting pressures on the nine-story portion of the Murrah Building due to this air-blast wave were a maximum of 10,000 psi at the area closest to the detonation and a minimum of 9 psi at the upper west corner of the structure