Meanwhile, Li Shimin submitted a secret accusation to Emperor Gaozu that Li Jiancheng and Li Yuanji were committing adultery with Emperor Gaozu's concubines and were planning to kill Li Shimin, and then laid an ambush for Li Jiancheng and Li Yuanji at Xuanwu Gate, at the entrance of Emperor Gaozu's palace. As Li Jiancheng and Li Yuanji were approaching Emperor Gaozu's palace, ready to answer the charges against them, they sensed that something was unusual, and tried to turn back. By this point, though, Li Shimin had them in a trap, and he killed Li Jiancheng with an arrow. Subsequently, Yuchi arrived with 70 men, and they killed Li Yuanji's horse, causing Li Yuanji to fall off his horse. Meanwhile, however, Li Shimin's horse was spooked and ran into a forest. Li Shimin fell off his horse, and Li Yuanji tried to kill him by strangling him with a bow. Yuchi then arrived, and Li Yuanji fled, trying to get back to his own palace Wude Palace (武德殿). Yuchi chased him and killed him with an arrow.