On March 16, 1968, C Company of Task Force Barker moved into the hamlet of My Lai in Quang Ngai province. The unit had suffered losses in the weeks before and had been told that Viet Cong forces were present in the village. Instead of encountering enemy fighters, however, the soldiers found unarmed villagers — mostly women, children, and the elderly. What followed became one of the darkest episodes of the Vietnam War.

The troops began systematically shooting the civilians. Commanding the platoon was Lieutenant William Calley, whose exact role remains disputed, but it is clear he made no effort to stop the massacre. By the end of the day, more than 500 villagers were dead. Initially, there was an effort to cover up what had happened, with reports filed that spoke of enemy combatants killed in action.

The truth might have remained hidden, but soldier Ronald Ridenhour, who had heard of the killings, persisted in demanding an investigation. His efforts eventually led to Calley’s court-martial. Calley was convicted and sentenced to life in prison, yet he ultimately served only three years under house arrest. The My Lai Massacre shocked the world, further eroded American support for the war, and remains a searing reminder of its moral costs.