Short answers, pulled from the story.
General Iwane Matsui led the Central China Area Army toward Nanjing, the capital of the Republic of China. He grew increasingly dismayed upon realizing the full extent of rape, torture, murder, and looting committed by his forces.
Japanese troops conducted mopping-up operations after capturing Nanjing on the 13th of December 1937. The International Committee for the Nanking Safety Zone was formed earlier on the 22nd of November 1937 to protect civilians before the city fell.
The International Military Tribunal for the Far East estimated more than 200,000 people were killed. Newer death toll estimates adhere to figures between 100,000 and 200,000 while other estimates vary from a low of 40,000 confined just to the city itself to over 340,000 encompassing the entire region.
Prince Yasuhiko Asaka received immunity as an imperial family member and was never tried for his role in the massacre. Hirohito singled out Prince Asaka in palace rolls for censure regarding his attitude toward the events.
German businessman John Rabe formed the International Committee for the Nanking Safety Zone on the 22nd of November 1937 to protect civilians. Minnie Vautrin sheltered up to 10,000 women at Ginling Girls College while Bernhard Arp Sindberg converted a cement factory into a refugee camp for 6,000 to 10,000 people.