The photos look like they are right out of a The Twilight Zone episode.
Operation Doorstep was a Civil Defense test carried out in conjunction with the much larger March 17, 1953, 16-kiloton ANNIE test conducted at the Nevada Test Site, part of Operation Upshot-Knothole.
In the smaller Operation Doorstep test, blast and thermal effects were evaluated on mannequins, automobiles, and wooden frame houses.
The facts:
Operation Doorstop
More Info and images are HERE.