Investigative journalist Seymour Hersh breaks the story of the My Lai massacre, which had occurred in Vietnam more than a year-and-a-half earlier but been covered up by military officials. That day, U.S. soldiers killed between 350 and 500 unarmed civilians, including women, the elderly, and infants. The event devastated America’s image internationally and galvanized the U.S. anti-war effort. For Hersh’s efforts he received a Pulitzer Prize.