The Mukden Incident, or Manchurian Incident, was a staged event engineered by Japanese military personnel as a pretext for the Japanese Invasion of Manchuria.
On September 18th 1931, Lt. Suemori Kawamoto detonated dynamite under a railway line owned by Japan's South Manchuria Railway near Mukden (now Shenyang) near Liutiáo Lake near Mukden at 10:20 PM under orders from his commanding officer. The area was chosen not because it was militarily important, but rather because it was straight and flat, meaning that rebuilding would be easy, and because there was a Chinese garrison less than 800 meters away, and thus, the Chinese could easily be blamed for the act. As it was, Lt. Suemori had planned to detonate the dynamite close to the railway so that it would be damaged but useable, but upon informing his commander that he planned to do this, he was ordered to place and detonate the dynamite under the railway lines, so that the damage was more extensive, and thus more blame could be placed on the Chinese. This order was to have tragic consequences for many people.
Minutes after Lt. Suemori detonated the dynamite, he looked on as a train travelling from Changchun to Shenyang approaches the destroyed section of track, unaware of the damage. Travelling at speed, the train derailed and the resulting accident killed seven civilians and injured dozens more.
The Imperial Japanese Army accused Chinese dissidents of the act and responded with a full invasion that led to the occupation of Manchuria, in which Japan established its puppet state of Manchukuo six months later. The ruse of war was soon exposed to the international community, leading Japan to diplomatic isolation and its March 1933 withdrawal from the League of Nations.