The Korean axe murder incident was the killing of two US Army officers, Captain Arthur Bonifas and First Lieutenant Mark Barrett, by North Korean soldiers on August 18, 1976, in the Joint Security Area in the Korean Demilitarized Zone. The US Army officers had been part of a work party cutting down a poplar tree in the JSA.
Three days later, American and South Korean forces launched Operation Paul Bunyan, an operation that cut down the tree with a show of force to intimidate North Korea into backing down, which occurred. North Korea then accepted responsibility for the earlier killings.
Wikipedia https://en.wikipedia.org/wiki/Korean_axe_murder_incident
Address (Unnamed Road), North Korea
Coordinates 37°57'21.86" N 126°40'21.539" E