At this point, having taken severe casualties, lacking artillery and cavalry cover, the high ground in enemy hands and the center being rolled up, the position for the Austrians deteriorated rapidly. The Second Prussian Army completely broke through the Austrian lines and took Chlum behind the center. The Army of the Elbe, which had merely held position after the early morning bloodying by the Austrian artillery and the Saxon infantry, attacked and broke through the Austrian left flank. It seized Probluz, and proceeded to destroy the Austrian flank. The Prussian king ordered all remaining forces into the attack all along the line, which had been slowed by the final counter-attack from the battalions of Brigadier General Ferdinand Rosenzweig von Dreuwehr's Austrian brigade. The arriving reinforcements joined the fight just as the Austrians had forced the 1st Prussian Guard back to Chlum. The result was a decisive shock of firepower which collapsed the Austrian line. The Prussian advance was so rapid that Benedek ordered a series of cavalry countercharges to back up his artillery and cover the general retreat he ordered at 15:00. These were successful at covering the Austrian rear, keeping the bridges over the Elbe open for retreating Austrian soldiers, and preventing pursuit by the Prussians, but at a terrible cost: 2,000 men and almost as many horses were killed, wounded or captured in the action. Benedek himself crossed the Elbe near 18:00 and several hours later informed the emperor that the catastrophe of which he had warned had indeed occurred.