The Union attackers assembled in the dark only about from the Confederate picket line and from the Confederate main line. Although vision was poor in the dark night, some defenders were alerted by the activity and began to fire randomly into the Union assembly area. The Union force took some casualties, including Brigadier General Lewis Grant who suffered a severe head wound and had to relinquish command to Lieutenant Colonel Amasa S. Tracy. Two regimental commanders in Colonel Thomas W. Hyde's brigade were mortally wounded. Despite the Confederate shooting, the Union troops were not allowed to return fire in order not to give away the planned attack. Getty's men had to lie on their arms on the cold ground for nearly four hours before the attack. Seymour's division was hard hit by shooting from Confederate pickets who had been provoked by firing from nearby Union outposts.