An estimate of the scale of the damage caused by the sixteen kt and 21 kt atomic bombings of Hiroshima and Nagasaki. The superior temperatures and radiation induce gas to move outward radially in a thin, dense shell identified as "the hydrodynamic front". The entrance acts similar to a piston https://radiationzone7daystodie40594.wikiparticularization.com/1440808/a_review_of_radiation_zone_facts