 On 14 June 1940, the day Paris fell, the German 1st Army went over to the offensive in "Operation Tiger" and attacked the Maginot Line between St. Avold and Saarbrücken.The Germans then broke through the fortification line as defending French forces retreated southward.In the following days, infantry divisions of the 1st Army attacked fortifications on each side of the penetration; capturing four petits ouvrages.