Introduction to the Huanggutun Incident: In 1928, the Northern Expeditionary Army of Chiang Kai-shek, Feng, Yan and Li attacked the Feng Clan, and the Feng Army collapsed across the board. On June 2, 1928, Zhang Zuolin announced his withdrawal from Beijing. At 6 o'clock in the evening on June 3, 1928, Zhang Zuolin left the Generalissimo's Palace in Beijing, took a large yellow steel plate bulletproof car made in Britain and was driven by Shaton, the director of the Fengtian Mortar Factory, and rushed to the train station. Accompanying them were Jin Yunpeng, Pan Fu, He Fenglin, Liu Zhe, Mo Huide, Yu Guohan, Yan Zepu, Zhang Zuolin's sixth concubine and third son Zhang Xuezeng, Japanese consultant Machino Kazuo and others. At 5:30 a.m. on June 4, when the special train Zhang Zuolin was riding passed the Sandong Bridge at the intersection of the Beijing-Fenghuang Railway and the South-Manchuria Railway, the train was blown up by explosives planted by the Japanese Kwantung Army. Zhang Zuolin was seriously injured and was sent back to Shenyang. Died on the same day.