5 psi overpressure at the Nevada Proving Ground in the 50's. Don't mess with rapidly moving air.
I haven't looked at the photos in extreme detail but a cursory looks reveals the concrete block walls were blown outward and the entire roof slab collapsed downward.
There was a good bit of stuff carried outward with the blast and mixed up in the concrete wall debris.
There was also a tangled mass of rebar that some how shed the concrete around it. Bad concrete that just fragmented into gravel or dust. That may have been at the point of impact. There was also a mangled truck shown. That may be another point of impact.
The photographers always zoom in on important points that never get described by the producers at home. The slab, the rebar and the truck were all repeatedly photographed as important..
I bet that parted his hair. :O)