earlier that afternoon, as meade realized the folly of sickles's movement, he ordered hancock to send a division from the ii corps to reinforce the iii corps. hancock sent the 1st division under brig. gen. john c. caldwell from its reserve position behind cemetery ridge. it arrived at about 6 p.m. and three brigades, under cols. samuel k. zook, patrick kelly (the irish brigade), and edward e. cross moved forward; the fourth brigade, under col. john r. brooke, was in reserve. zook and kelly drove the confederates from stony hill, and cross cleared the wheatfield, pushing kershaw's men back to the edge of rose woods. both zook and cross were mortally wounded in leading their brigades through these assaults, as was confederate semmes. when cross's men had exhausted their ammunition, caldwell ordered brooke to relieve them. by this time, however, the union position in the peach orchard had collapsed (see next section), and wofford's assault continued down the wheatfield road, taking stony hill and flanking the union forces in the wheatfield. brooke's brigade in rose woods had to retreat in some disorder. sweitzer's brigade was sent in to delay the confederate assault, and they did this effectively in vicious hand-to-hand combat. the wheatfield changed hands once again.