The blow fell on the morning of May 27th. The front selected for the assault was twenty-five miles in width, extending from the Ailette near Vauxaillon to the Aisne-Marne Canal near Brimont. The Prussian Crown Prince was the titular chief of the group of armies used in the assault. One of these forces was the army of General von Boehm, which before the attack had numbered only nine divisions and had extended from the Oise at Noyon to east of Craconne. The other army was that of General Fritz von Buelow, previously composed of eight divisions and supporting a front that extended from Craconne across the Rheims front to Suippe, near Auberive. On the day of the attack, these armies had been strengthened to twice their normal number of divisions, and subsequently captured German plans revealed that the enemy expected to use forty-five divisions or practically half a million men in the onslaught. The battle began at dawn. It was directed against the weakly held French positions on the Chemin des Dames. It was preceded by a three hour bombardment of terrific intensity. The French defenders were outnumbered four to one. The Germans put down a rolling barrage that was two miles deep. It destroyed all wire communications and flooded battery emplacements and machine gun posts with every brand of poison gas known to German kultur. Dust and artificial smoke clouds separated the defenders into small groups and screened the attacking waves until they had actually penetrated the French positions. The French fought hard to resist the enemy flood across the Chemin des Dames with its ground sacred with tragic memories, but a withdrawal was necessary. The French command was forced to order a retreat to the Aisne. Hard-fighting French divisions and some units of the British Fifth Army, which had been badly hit in Picardy in March, made an orderly withdrawal southward. On the second day of the fight the enemy made a strong thrust toward Soissons, and after keeping the city under continual bombardment, succeeded in overcoming all resistance and occupying the city on May 29th. On the first day of the attack alone, twelve thousand explosive, incendiary and poison gas shells were hurled in amongst the hospitals in Soissons. American ambulance units did heroic work in the removal of the wounded. The Germans forced a crossing on the Aisne. On the following day, May 30th, they had crossed the Vesle River and had captured Fere-en-Tardenois. On the following day their victorious hordes had reached the Marne and were closing in on Chateau-Thierry.