Geshu, and Geshu, in turn apprehensive that Yang was going to act against him, found an excuse to execute Du, further causing Yang's suspicions. Yang therefore had Emperor Xuanzong order Geshu to engage An's forward commander Cui Qianyou (), despite Geshu's repeated protestations that a battle was inadvisable. Once the armies engaged, Tang forces were crushed by Cui's forces; Geshu was captured, and Tong Pass fell on July 10. Yang then began to plan for an evacuation to Jiannan. Emperor Xuanzong agreed. On July 14, the imperial train, without announcing to the people of Chang'an, left Chang'an, with Emperor Xuanzong attended to by the imperial clan members, Yang, Wei Jiansu, the official Wei Fangjin (), the general Chen Xuanli (), and eunuchs and ladies in waiting close to the emperor. On July 15, Emperor Xuanzong's train reached Mawei Station (馬嵬驛, in modern Xianyang, Shaanxi). The imperial guards were not fed and were angry at Yang Guozhong. Chen also believed that Yang Guozhong provoked this disaster and planned to kill him—and reported his plans to Li Heng through Li Heng's eunuch Li Fuguo, but Li Heng was hesitated and gave no approval. Meanwhile, though, emissaries of the Tibetan Empire, who had followed Emperor Xuanzong south, were meeting with Yang Guozhong and complaining that they were also not fed. The imperial guard soldiers took this opportunity to proclaim that Yang Guozhong was planning treason along with the Tibetan emissaries, and they killed him, along with his son Yang Xuan (), the Ladies of Han and Qin, and Wei Fangjin. Wei Jiansu was also nearly killed, but was spared at the last moment with severe injuries. The soldiers then surrounded Emperor Xuanzong's pavilion, and refused to scatter even after Emperor Xuanzong came out to comfort them and order them to scatter. Chen publicly urged him to put Consort Yang to death—which Emperor Xuanzong initially declined. After Wei Jiansu's son Wei E () and Gao Lishi spoke further, Emperor Xuanzong finally resolved to do so. He therefore had Gao take Consort Yang to a Buddhist shrine and allow her a forced suicide, considered a more dignified death than outright execution. After he showed the body to Chen and the other imperial guard generals, the guard soldiers finally scattered and prepared for further movement. Meanwhile, Yang Guozhong's wife Pei Rou, son Yang Xi (), the Lady of Guo, and the Lady of Guo's son Pei