Nick Ut, 1972. Phan Thị Kim Phúc fleeing a napalm strike in Trảng Bàng, Vietnam. Pulitzer Prize 1973; later catalyst for ending the war.
From Wikipedia
The Terror of War, colloquially known as Napalm Girl, is a photograph taken on 8 June 1972. It shows a naked 9-year-old girl, Phan Thi Kim Phuc, running toward the camera from a South Vietnamese napalm strike that mistakenly hit Trảng Bàng village instead of nearby North Vietnamese troops. It is credited as one of the most famous images of the Vietnam War and an indictment of the effects of war on innocent victims in general.