[180] Initially the diversionary attack against Siberia and subsequent assault against Bunker had been made by Marines of 2/1 since Siberia was in the 2/1 sector. On 12 August operational control was transferred to 3/1 as the fighting continued at Bunker, in the area of responsibility of the left battalion sector. Actually, more than an hour elapsed before the Communists initiated their first main ground attack to regain Bunker. By that time, heavy casualties from the continued shelling had forced Company B to pull back from the ridge and take up positions on the reverse (eastern) slope of Bunker Hill. At this point, with reduced Company B forces and with no radio communication between Captain Scranton’s unit and 3/1, Lieutenant Colonel Armitage sent I/3/1,[181] under Captain Howard J. Connolly, forward from the MLR. Shortly before 1600, a force of more than 350 Chinese lunged out of the low ground of Hill 123, west of Bunker, to attack defensive positions along the ridge between Hills 124–122. Striking in rapid succession first the west side and then the northern end of the Company B position to find a weak spot in the defense, the enemy counterattack finally concentrated on the southwestern part of the hill. [181] From the division reserve, Captain Anthony J. Skotnicki’s company, I/3/7, was en route to take over the I/3/1 sector. As an interim measure, Captain Byron J. Melancon’s Company H extended its MLR positions to the right to cover the Company I area. An intense exchange of fire raged here until 1715, when the defending fire of Company B plus the added weight of the Company I reinforcements combined to stall the enemy advance. Having failed to gain their objective, the Communists abruptly broke off their artillery and mortar fire and ordered their infantry to withdraw. They pulled back only to the far side of the hill, however. By 1740 the enemy was occupying his new post on the northern slope, while the Marines continued to hold their positions on the reverse slope of Bunker Ridge. Enemy supporting fires had lifted and a lull ensued in the fighting. _Consolidating the Defense of Bunker Hill_[182] [182] Unless otherwise noted, the material for this section is derived from: 1stMarDiv ComdD, Aug 52; 1stMarDiv G-3 Jnl, 12–13 Aug 52; 1stMar, 1/1, 3/1 ComdDs, Aug 52.