For my research essay of the Vietnam era I chose the topic of The My Lai Massacre. The massacre took place on March 16, 1968; roughly 3 years after the US first sent troops to Vietnam. The Charlie Company of the 11th Infantry Brigade had been sent to My Lai on a search and destroy mission, to remove a Viet Cong battalion that was thought to be in the area. When they arrived in My Lai, the American crew met no opposition, only finding the nearly 700 inhabitants eating breakfast. Despite finding none of the inhabitants to be of fighting age, most children, elderly, or woman the Americans fired upon the civilians. Led by Second Lieutenant William Calley, the crew began killing the civilians mercilessly. Based of off first-hand accounts from US soldiers, a large group of Vietnamese, including women and children, were killed lined up in front of a drainage ditch before being executed. During the massacre, an American helicopter crew spotted the killing, and promptly landed to confront their allies. Many of the ground soldiers claimed they were following orders, others responded that the only help these civilians would get was a "hand grenade". Soon after, the chopper crew was able to convince some soldiers to allow some young civilians to be evacuated, rather than killed. In the end, the soldiers killed somewhere between 347 (reported by the US government) to 504 (reported by Vietnamese government) civilians in the massacre. On top of the killing, the culprits attempted to cover up the killings, reporting that "128 Viet Cong and 22 civilians" were killed in the raid of My Lai. After lengthy investigation, however, it was decided that nearly 30 troops could be charged with war crimes. Despite this, only one, Second Lieutenant William Calley was charged.
Best Source: http://www.digitalhistory.uh.edu/active_learning/explorations/vietnam/vietnam_mylai.cfm