This marked the first stage of the final phase in the Chinese Civil War. Knowing their disadvantages in manpower and equipment, the CPC executed a "passive defense" strategy. It avoided the strong points of the KMT army and was prepared to abandon territory in order to preserve its forces. In most cases the surrounding countryside and small towns had come under Communist influence long before the cities. The CPC also attempted to wear out the KMT forces as much as possible. This tactic seemed to be successful; after a year, the power balance became more favorable to the CPC. They wiped out 1.12 million KMT troops, while their strength grew to about two million men. In March 1947 the KMT achieved a symbolic victory by seizing the CPC capital of Yan'an. The Communists counterattacked soon afterwards; on 30 June 1947 CPC troops crossed the Yellow River and moved to the Dabie Mountains area, restored and developed the Central Plain. At the same time, Communist forces also began to counterattack in Northeastern China, North China and East China. By late 1948, the CPC eventually captured the northern cities of Shenyang and Changchun and seized control of the Northeast after suffering numerous setbacks while trying to take the cities, with the decisive Liaoshen Campaign. The New 1st Army, regarded as the best KMT army, was forced to surrender after the CPC conducted a brutal six-month siege of Changchun that resulted in more than 150,000 civilian deaths from starvation. The capture of large KMT units provided the CPC with the tanks, heavy artillery and other combined-arms assets needed to execute offensive operations south of the Great Wall. By April 1948 the city of Luoyang fell, cutting the KMT army off from Xi'an. Following a fierce battle, the CPC captured Jinan and Shandong province on 24 September 1948. The Huaihai Campaign of late 1948 and early 1949 secured east-central China for the CPC. The outcome of these encounters were decisive for the military outcome of the civil war. The Pingjin Campaign resulted in the Communist conquest of northern China. It lasted 64 days, from 21 November 1948 to 31 January 1949. The PLA suffered heavy casualties while securing Zhangjiakou, Tianjin along with its port and garrison at Dagu and Beiping. The CPC brought 890,000 troops from the northeast to oppose some 600,000 KMT troops. There were 40,000 CPC casualties at Zhangjiakou alone. They in turn killed, wounded or captured some 520,000 KMT during the campaign.