Meanwhile, while Zhao was in negotiations with the Khitan, the situation at Jin'an became desperate for the Later Tang remnants there. Eventually, Zhang's deputy Yang Guangyuan assassinated him and surrendered to Khitan/Later Jin. Emperor Taizong gave the Later Tang army to Shi, and they jointly prepared to head south toward Luoyang. They engaged Zhao's army at Tuanbo Valley (團柏谷, in modern Taiyuan), crushing it. Zhao fled to Lu Prefecture (潞州, in modern Changzhi, Shanxi) and, believing he could not hold it against the coming torrent of Khitan/Later Jin forces, surrendered, leaving Shi's path toward Luoyang clear. Emperor Taizong, citing the fact that the Han Chinese may be fearful of Khitan soldiers, stopped at Lu himself and had Shi advance toward Luoyang by himself. Believing the situation to be hopeless, Li Congke gathered his family (including Empress Dowager Cao, who decided to die with her stepson's family rather than to live) and a number of officers still loyal to him, and committed suicide by immolation on Xuanwu Tower () inside the palace. Shi subsequently entered Luoyang and assumed control over the Later Tang realm.