A 6- by 6- by 36-ft structure was subjected to a nonideal wave front with an overpressure of about 14 psi at 1850 ft from a 43 plus or minus 2 kt, 500-ft tower burst. The structure was demolished by the blast, but records were obtained for an average of 580 msec before the signal cables were torn out or broken. The precursor was weaker than expected. Peak overpressures on the front of the structure were in excess of 100 psi, indicating an unexpectcdly high contribution from the drag pressure. (auth)