The Atom Strikes! (1945)

This official U.S. War Department Film (Misc. 1235) reports on the damage done by the atomic bombings of Hiroshima and Nagasaki. Blast, flash/heat, and radiation effects are examined, starting from ground-zero and working outwards. The film also contains an interview with a Jesuit priest who was present in Hiroshima on the day of the explosion.