The post was located approximately 400 meters from the western end of the airstrip and north of where the Company L, 3/26 lines tied in with those of 1/26. At 2030, a sentry dog was alerted by movement outside the perimeter and a few minutes later the Marines manning the post reported that six unidentified persons were approaching the defensive wire. Oddly enough, the nocturnal visitors were not crawling or attempting to hide their presence; they were walking around as if they owned the place. A squad from L/3/26, headed by Second Lieutenant Nile B. Buffington, was dispatched to investigate. Earlier in the day the squad had rehearsed the proper procedure for relieving the listening post and had received a briefing on fire discipline. The training was shortly put to good use. Lieutenant Buffington saw that the six men were dressed like Marines and, while no friendly patrols were reported in the area, he challenged the strangers in clear English to be sure. There was no reply. A second challenge was issued and, this time, the lieutenant saw one of the men make a motion as if going for a hand grenade. The Marines opened fire and quickly cut down five of the six intruders. One enemy soldier died with his finger inserted in the pin of a grenade. The awesome hitting power of the M-16 rifle was quite evident since all five men were apparently dead by the time they hit the ground. The lone survivor was wounded but managed to escape after retrieving some papers from a mapcase which was on one of the bodies. Using a sentry dog, the Marines followed a trail of blood to the southwest but gave up the hunt in the darkness. The direction the enemy soldier was heading led the Marines to believe that his unit was located beyond the rock quarry. The importance of the contact was not realized until later when intelligence personnel discovered that all five of the enemy dead were officers including an NVA regimental commander, operations officer, and communications officer. The fact that the North Vietnamese would commit such key men to a highly dangerous, personal reconnaissance indicated that Khe Sanh was back at the top of the Communists' priority list.(36)