 On the left flank of the attack, Brockenbrough's brigade was devastated by artillery fire from Cemetery Hill. They were also subjected to a surprise musket fusillade from the 8th Ohio Infantry regiment. The 160 Ohioans, firing from a single line, so surprised Brockenbrough's Virginians — already demoralized by their losses to artillery fire — that they panicked and fled back to Seminary Ridge, crashing through Trimble's division and causing many of his men to bolt as well. The Ohioans followed up with a successful flanking attack on Davis's brigade of Mississippians and North Carolinians, which was now the left flank of Pettigrew's division. The survivors were subjected to increasing artillery fire from Cemetery Hill. More than 1,600 rounds were fired at Pettigrew's men during the assault. This portion of the assault never advanced much farther than the sturdy fence at the Emmitsburg Road. By this time, the Confederates were close enough to be fired on by artillery canister and Alexander Hays' division unleashed very effective musketry fire from behind 260 yards of stone wall, with every rifleman of the division lined up as many as four deep, exchanging places in line as they fired and then fell back to reload.
