While on an assignment in Europe during World War II, newreel reporter Mack Snelling was captured by the Nazi’s, who not only tortured him, but also used him as an experimental test subject. Needless to say, one of the experiments gives him super speed and he makes his escape! Adopting the ugliest costume ever seen on a superhero (a yellow and green outfit with a red crest and goggles) Mack decides to fight the Nazis with the weapon they gave him, mocking them by adopting a German name.
The Blitz becomes a founder member of the Knights of Justice. When his fiance needs an emergency blood transfusion from him, she too acquires super speed and becomes a heroine in her own right, the Speed Queen.
He eventually traded places briefly with the Blitz of Earth A during the Criss Cross Crisis.