Having received his pontoon bridges, General Burnside prepared to throw his grand army across the river. At two o'clock on the morning of Thursday, December the 11th, his troops were put in motion and two signal guns from the Confederate side, at five o'clock,[29] sounded a note of warning to the people and the army. General Burnside commenced throwing three pontoon bridges across the Rappahannock river. One was to span the river at French John's wharf, at the foot of Hawke street, one at Scott's Ferry, at the lower end of Water street, and one at Deep Run, about two and a half miles below town. General Wm. Barksdale's brigade, consisting of the Thirteenth, Seventeenth, Eighteenth and Twenty-first Mississippi regiments, held the town. "General Barksdale kept his men quiet and concealed until the bridges were so far advanced that the working parties were in easy range, when he opened fire with such effect that the bridges were abandoned at once. Nine separate and desperate attempts were made to complete the bridges under fire of their sharpshooters and guns on the opposite bank, but every attempt being attended with such severe loss from the Confederates, posted in rifle-pits, in the cellars of the houses along the banks, and behind whatever offered concealment, that the enemy abandoned their attempts and opened a terrific fire from their numerous batteries concentrated along the hills just above the river. The fire was so severe that the men could not use their rifles, and, the different places occupied by them becoming untenable, the troops were withdrawn from the river bank back to Caroline street at 4:30 P. M. The enemy then crossed in boats, and, completing their bridges, passed over in force and advanced into the town. The Seventeenth Mississippi and ten sharpshooters from Colonel J. W. Carter's regiment (the 13th) and three companies of the Eighteenth regiment, Lieutenant Colonel Luse, under Lieutenant William Ratliff, were all the troops that were actually engaged in defending the crossings in front of the city."[30] The other regiments and parts of regiments were held in reserve, and were not brought into action until the enemy had crossed the river. At the first dawn of light on the morning of December the 11th the Federal artillery commenced its work of destruction. From the heights above the town of Falmouth, north of Fredericksburg, to the Washington farm below, on every available place artillery was stationed, bearing upon the town. About one hundred and seventy-five of the grim monsters, ready to "belch forth death and destruction," were placed in position the day before, well manned, and only waiting for the signal to send forth their deadly messengers of shot and shell.