From the obit:

In January 1966 he joined a battalion of US soldiers seeking to rout North Vietnamese snipers and was standing next to the battalion commander when the soldier paused to read a map.

"As the colonel peered at it I heard four loud shots as bullets tore through the map and into his chest, a few inches from my face," Arnett recalled during a talk to the American Library Association in 2013. "He sank to the ground at my feet."

He would begin the fallen soldier's obituary like this: "He was the son of a general, a West Pointer and a battalion commander. But Lt. Colonel George Eyster was to die like a rifleman. It may have been the colonel's leaves of rank on his collar, or the map he held in his hand, or just a wayward chance that the Viet Cong sniper chose Eyster from the five of us standing in that dusty jungle path."