Allied forces break through the Hindenburg Line

On September 29, 1918, during WWI, Allied forces scored a decisive breakthrough of the Hindenburg Line. An excerpt from the article:

"On September 29, 1918, after a 56-hour-long bombardment, Allied forces breach the so-called Hindenburg Line, the last line of German defenses on the Western Front during World War I.

Built in late 1916, the Hindenburg Line—named by the British for the German commander in chief, Paul von Hindenburg; it was known to the Germans as the Siegfried Line—was a heavily fortified zone running several miles behind the active front between the north coast of France and Verdun, near the border of France and Belgium. By September 1918, the formidable system consisted of six defensive lines, forming a zone some 6,000 yards deep, ribbed with lengths of barbed wire and dotted with concrete emplacements, or firing positions. Though the entire line was heavily fortified, its southern part was most vulnerable to attack, as it included the St. Quentin Canal and was not out of sight from artillery observation by the enemy. Also, the whole system was laid out linearly, as opposed to newer constructions that had adapted to more recent developments in firepower and were built with scattered “strong points” laid out like a checkerboard to enhance the intensity of artillery fire."