JF Ptak Science Books Quick Post
No, this family wasn't killed by a firing squad, but according to the pamphlet they might as well have been. By the 7th column.
The 5th Column is the army of spies and saboteurs infiltrating a country; the 6th Column helps this action along, (according to Webster's): "the aggregate of persons in a country at war who assist the subversive activities of the fifth column by defeatist talk, the spreading of rumors, and other activities that weaken resistance or appease the enemy".
The 7th column was carelessness--and evidently this was a push to roll back the tide of accidental death and injury in the U.S., something that was particularly important during wartime. According to this tract 102,500 Americans were accidentally killed every year, with another 350,000 becoming permanently disabled and 9,000,000 being injured. "We must stop burning down our factories" says the author, for these injuries and deaths would be along the same lines (in some fashion) of the U.S. being bombed.
This seems as though it could have been an effective tool in getting the view across of fighting the sub-rosa enemy of carelessness in wartime.