The My Lai Massacre was the mass murder of 347 to 504 unarmed citizens of the Republic of Vietnam (South Vietnam), mostly civilians and majority of them women and children, conducted by U.S. Army forces on March 16, 1968. The massacre took place in the hamlets of M? Lai and My Khe of Son M? village during the Vietnam War.The incident prompted widespread outrage around the world and reduced U.S. support at home for the Vietnam War. The massacre is also known as the Son My Massacre.