Second stage After thorough preparation, the communist II and XIX Corps attacked the city again on August 25, 1949, at dawn, and by dusk, the nationalist stronghold at Southern Mountain outside the city fell into the enemy hands. After suffering heavy casualties, the nationalist morale collapsed and the defenders outside the city fled inside and Ma Jiyuan (), the nationalist commander-in-chief of the Shaanxi-Gansu Corps fled to Xining in the evening, abandoning most of his troops. In the morning of August 26, 1949, a detachment of the communist 3rd Army took Western Pass () of the city and then took the Iron Bridge on the Yellow River, thus successfully cutting off the only escape route of the defenders, while other enemy detachments also managed to successfully breaching the defense of the city and begun fierce street fights with the remaining nationalist garrison. By 11:00 AM, the communist 4th Army took White Pagoda Mountain (Bai Ta Shan, ) on the northern bank of the Yellow River and an hour later, the last nationalist resistance within the city wall was eliminated and the city was firmly in the enemy hands. After the completion of the mop up operations in the suburb on the next day, the enemy formally declared the city was secured on August 27, 1949. The 5,000 Chinese Muslim defenders in Lanzhou inflicted 10,000 casualties upon the Communist 2nd army during the six-day battle. In order to relieve the besieged city, the nationalists organized several futile reinforcement attempts: nationalist commander Hu Zongnan ordered four armies to launch an offensive on August 27, 1949, from southern Gansu toward regions including Xihe and Li Counties in Gansu, and Baoji, Duo Town (Duo Zhen, ) in Shaanxi, in the hope of taking Baoji and Tianshui, thus forcing the enemy to stop the attack on Lanzhou and reinforce these regions. However, as the news of the fall of Lanzhou was learned, the nationalist offensive fell apart as the nationalist morale immediately collapsed, and the futile offensive was beaten back by the communist XVIII Corps on the same day it was launched. Learning the news of the fall of Lanzhou, other nationalist reinforcement also immediately withdrew: Ma Hongkui's nationalist 81st Army withdrew back to Ningxia and Ma Bufang's nationalist 91st Army and the nationalist 120th Army retreated to Hexi Corridor. Outcome The fall of Lanzhou cost the nationalists more than 42,000 troops, nearly half of