The first nuclear blast broadcast live on television took place March 17, 1953, in northwestern Nevada. Operation Doorstep was meant to determine the effect of a 16-kiloton nuclear explosion on fifty automobiles, two wood-frame houses, eight backyard bomb shelters, and a goodly number of mannequins. The houses were built specially for the test, and the other objects were carefully arranged, as though for a dollhouse. The ostensible purpose of all this was “to show the people of America what might be expected if an atomic burst took place over the doorsteps of our major cities.”
https://publicdomainreview.org/collection/operation-doorstep-1953
