Initial trimming
On August 18, 1976, a group of five Korean Service Corps (KSC) personnel escorted by a UNC security team consisting of Bonifas, his South Korean (ROK) Army counterpart, Captain Kim, the platoon leader of the current platoon in the area (1LT Mark Barrett), and 11 enlisted personnel, both American and South Korean,[2] went into the JSA to trim the tree as previously scheduled with the KPA delegation.
The two captains did not wear side arms, as members of the Joint Security Area were limited to only five armed officers and 30 armed enlisted personnel at a time. However, there were mattocks in the back of the 2½ ton truck. The KSC workers had the axes they brought to prune the tree branches. The tree had been scheduled to be trimmed seven days earlier, but rain had forced the work to be rescheduled.
After trimming began, 15 to 16 North Korean soldiers appeared, commanded by Senior Lt. Pak Chul, whom the UNC soldiers had previously nicknamed "Lt. Bulldog" due to a history of confrontations.[3][4] Pak and his subordinates appeared to observe the trimming without concern for approximately 15 minutes, until he abruptly told the UNC to cease the activity stating the tree could not be trimmed "because Kim Il Sung personally planted it and nourished it and it's growing under his supervision."[5] Capt. Bonifas ordered the detail to continue, and turned his back on Lt. Pak Chul.[6]
Attack
After being ignored by Capt. Bonifas, Pak sent a runner across the Bridge of No Return. Within minutes a North Korean guard truck crossed the bridge and approximately 20 more North Korean guards disembarked carrying crowbars and clubs. Pak again demanded that the tree trimming stop, and when Capt. Bonifas again turned his back on him, Pak removed his watch, carefully wrapped it in a handkerchief, placed it in his pocket, and then shouted "Kill the bastards!" as he swung a karate chop to the back of Capt. Bonifas' neck.[6][7] Using axes dropped by the tree-trimmers, the KPA forces attacked the two U.S. soldiers, Capt. Bonifas and Lt. Barrett, and wounded all but one of the UNC guards.[3][8]
While Capt. Bonifas died instantly, Lt. Barrett jumped a low wall which led into a 15 ft. (4½ m) deep tree-filled depression, just across the road from the tree. The depression was not visible from the road because of the dense grass and small trees. The entire fight lasted for only about 20–30 seconds before the UNC Force managed to disperse the North Korean guards and place Capt. Bonifas' body in their truck.[7] However, there was no sign of Lt. Barrett and the two UNC guards at OP#5 could not see