Or more accurately a recalc, of this one specifically. The math is fine, but the overpressure used is wrong, the old calc uses 6 and 9 psi, but as I brought up in the CRT/discussion thread (Because that's basically what that's turned into) the explosion only causes a building to fall over, while the originally used overpressure would have blown the building apart, which, according to this chart, fits best with 3 psi, the point at which "most residential buildings collapse," or 5 psi, where most buildings (Not just residential ones) collapse
Low End[]
19.329^3*((27136*0.21+8649)^(1/2)/13568-93/13568)^2 = 0.02814 Tons of TNT, 9-A/Small Building level
High End[]
19.329^3*((27136*0.34+8649)^(1/2)/13568-93/13568)^2 = 0.06498 Tons of TNT, 9-A/Small Building level
Both are still 9-A, but lower than the original.