Panmunjom Axe Murder Incident
Also called: Poplar Tree Incident
Two US Army officers supervising the trimming of a poplar tree in the Joint Security Area at Panmunjom were killed by North Korean soldiers with axes; afterwards a dividing line was drawn even inside the JSA.

Service Depicted: Army Camera Operator: SPC 4 LONG · Public domain · Source
On 18 August 1976, while a poplar tree that blocked the view from a UN Command post in the Joint Security Area was being trimmed, North Korean soldiers who had demanded that the work stop attacked with axes and clubs. Captain Arthur Bonifas and Lieutenant Mark Barrett, the US officers supervising the work, were killed and several South Korean and American soldiers wounded.
With an aircraft carrier and bombers deployed around the peninsula and US forces at DEFCON 3, South Korean and US troops cut the tree down on 21 August (Operation Paul Bunyan). North Korea conveyed regret in Kim Il Sung’s name, and the Military Demarcation Line was then marked inside the JSA, with guards of each side keeping to their own half.