The Confederate artillery bombardment preceding Pickett's Charge on July 3 battered Cemetery Ridge, and Union artillery on the ridge counterfired to Seminary Ridge. Thirty-four Union cannons were disabled, but the three Confederate divisions of the subsequent infantry assault (Pickett's of the First Corps and Pettigrew's and Trimble's of the Third Corps), attacked the Union II Corps at the "stone fence" at the Angle. Heavy rifle and artillery fire prevented all but about 250 Confederates led by Lewis Armistead from penetrating the Union line to the high water mark of the Confederacy. Armistead was mortally wounded. Two brigades of Anderson's Division, assigned to protect Pickett's right flank during the charge, reached a more southern portion of the Union line at Cemetery Ridge soon after the repulse of Pickett's Division, but were driven back with 40% casualties by the 2nd Vermont Brigade.