The next morning his train reached the outskirts of Shenyang. Here the line passed through the Japanese-operated South Manchuria Railroad. In what came to be known as the Huanggutun incident, Col. Kōmoto Daisaku, an officer of the Japanese Kwantung Army, planted a bomb along a railroad bridge, which exploded when Zhang's train passed under it; mortally wounded, Zhang died a few hours later. At the Tokyo War Crimes Tribunal in 1946, Okada Keisuke testified that Zhang was murdered because the Kwantung Army was infuriated by his failure to stop Chiang's army, which was backed by Moscow; Tokyo's strategic rival. For two weeks Zhang's death was kept secret while the scramble for power was decided. That is why, according to an announcement issued by the Fengtian Army, he officially died on 21 June 1928.