The 1923 Great Kantō earthquake strucks with magnitude of 7.9 the Kantō Plain on the Japanese main island of Honshū. The earthquake is an event takes place in the movie The Wind Rises written and directed by Hayao Miyazaki of Studio Ghibli.
When Jirō Horikoshi is traveling by train, the earthquake roars and the train gets suddenly derailed. Tokyo burns in flames. Jiro finds Nahoko Satomi safe and sound. But her friend Kinu broke her leg. Jiro splints her leg by using his slide ruler and help her to get to Ueno, where Naoko lives. Then, he is leaving without giving his name.
See also wikipedia:1923 Great Kantō earthquake.