Here you go

These guys are libs (albiet fairly pro China libs run by Kevin Rudd) but give some context if you can cope with the brainworms

https://asiasociety.org/education/massacre-nogun-ri

The wiki page goes into the whole thing fairly well, at least for Wikipedia.

https://en.wikipedia.org/wiki/No_Gun_Ri_massacre (cw: violence, war crimes, premeditated crimes against humanity described in detail)

Some key quotes, sparing the nightmare fuel.

Major General William B. Kean of the neighbouring 25th Infantry Division advised that any civilians found in areas supposed to be cleared by police should be considered enemies and "treated accordingly", an order relayed by his staff as "considered as unfriendly and shot"

Researchers found that the U.S. review had not disclosed the existence of U.S. Air Force mission reports during this period documenting the strafing of apparent refugee groups and air strikes in the No Gun Ri vicinity.

After the Army issued its report, it was learned that it also had not disclosed its researchers' discovery of at least 14 additional declassified documents showing high-ranking commanders ordering or authorizing the shooting of refugees in the Korean War's early months,  such as communications from 1st Cavalry Division commander Gay and a top division officer to consider refugees north of the front line "fair game" and to "shoot all refugees coming across river"

In 2005, American historian Sahr Conway-Lanz reported his discovery of a declassified document at the National Archives in which the United States Ambassador to Korea in 1950, John J. Muccio, notified the State Department on the day the No Gun Ri killings began that the U.S. military, fearing infiltrators, had adopted a policy of shooting South Korean refugee groups that approached U.S. lines despite warning shots. Pressed by the South Korean government, the Pentagon eventually acknowledged it deliberately omitted the Muccio letter from its 2001 report.

By 2009, the commission's work of collating declassified U.S. military documents with survivors' accounts confirmed eight representative cases of what it found were wrongful U.S. killings of hundreds of South Korean civilians, including refugees crowded into a cave attacked with napalm bombs, and those at a shoreline refugee encampment deliberately shelled by a U.S. warship.

The commission alleged that the U.S. military repeatedly conducted indiscriminate attacks, failing to distinguish between combatants and non-combatants. In its most significant finding, the commission also confirmed that South Korean authorities had summarily executed thousands of suspected leftists in South Korea – possibly 100,000 to 200,000 – in the Bodo League massacre at the outbreak of the war, sometimes with U.S. Army officers present and taking photographs.

And finally

The disclosure in 2006 that Pentagon investigators had omitted the Muccio letter from their final report, along with other incriminating documents and testimony, prompted more calls for action. Two leaders of the National Assembly appealed to U.S. Senator (and future president) Joseph R. Biden, chairman of the U.S. Senate Foreign Relations Committee, for a joint investigation, but no U.S. congressional body ever took up the No Gun Ri issue.