The massacre occurred on 16 March 1968.
The hero that DMan mentions, the helicopter pilot, was Hugh Thompson. His door gunner was Lawrence Colburn. The third member of the crew was Glenn Andreotta. Thompson, 24, when he realized the massacre was taking place, landed and tried to save villagers. He ordered his crew to fire on fellow American troops if need be, while they airlifted survivors to safety. He was armed only with a handgun.
Thompson got the Distinguished Flying Cross shortly after and his crew got bronze stars, but he thought it was to try to shut him up. The true story of their courage went largely unreported for thirty years.
On 6 March 1998 Hugh Thompson and Lawrence Colburn were honoured with the Soldier's Medal in a ceremony at the Vietnam Veterans Memorial. The Soldier's Medal is awarded for risking one's life when an enemy army is not involved. Glenn Andreotta died in a helicopter crash in Vietnam shortly after the My Lai massacre. He was awarded the Soldier's Medal posthumously, at Thompson's insistence.
Thompson and Colburn also received the Courage of Conscience Award from the Peace Abbey.
It's not often I cry reading a newspaper in a public library.