https://en.wikipedia.org/wiki/Korean_axe_murder_incident

...was the killing of two United States Army officers, CPT Arthur Bonifas and 1LT Mark Barrett, by North Korean soldiers on August 18, 1976, in the Joint Security Area (JSA) located in the Korean Demilitarized Zone (DMZ). The U.S. Army officers had been part of a work party cutting down a poplar tree in the JSA.

Afterwards as a response to the killing...a convoy of 23 American and South Korean vehicles... In the vehicles were two eight-man teams of military engineers...accompanied by two 30-man security platoons from the Joint Security Force...In addition, a 64-man task force of the South Korean 1st Special Forces Brigade accompanied them... U.S. infantry company in 20 utility helicopters and seven Cobra attack helicopters circled behind them. Behind these helicopters, B-52 Stratofortresses came from Guam escorted by U.S. F-4 Phantom IIs from Kunsan Air Base and South Korean F-5 and F-86 fighters were visible flying across the sky at high altitude. At Taegu Air Base, F-111 bombers of the 366th Tactical Fighter Wing out of Mountain Home Air Force Base, were stationed, and F-4C and -D Phantoms from the 18th TFW Kadena Air Base and Clark Air Base were also deployed. The aircraft carrier USS Midway task force had also been moved to a station just offshore....n addition, 12,000 additional troops were ordered to Korea, including 1,800 Marines from Okinawa...
...cut down the tree.