On the 16th March 1968, the My Lai Massacre occurred in South Vietnam. 350-500 men, women, children and babies were brutally killed by US troops during a counterinsurgency operation. It was the worst war crime perpetrated by US forces during the Vietnam War. 

To try and find out what made those men snap and commit those terrible crimes I spoke to Erik Villard a Historian at the U.S. Army Center of Military History, Fort McNair, DC. He talks us through the events of that fateful day, why he believes it took place and how these shocking events continue to influence US military operations today.