Original director William Berke died of a sudden heart attack on the first day of shooting. His son, Lester Wm. Berke, took over.
The concept of the atomic-powered cruise missile doomsday weapon was similar to that of the U.S. Air Force's Supersonic Low Altitude Missile, which was under development at the time.
Scenes of Ottawa residents entering shelters were either shot somewhere in Canada or the property master had an eye for detail: the shelter signage is in both English and French (shelter/abri).
The film refers to Havenbrook Atomic Laboratory in suburban New York City. The actual Brookhaven National Laboratory is in Brookhaven, L.I., N.Y.
A low-budget film that relied heavily on stock footage of military forces and civil defense exercises, it carried a Cold War-era message of the importance of the work done by scientists and the military in protecting the nation from external threats.