Private Barker was killed by shell fragments from a North Vietnamese Army artillery projectile when his company was attacked by a well entrenched North Vietnamese battalion defending the strategic village of Nhi Ha. Cross cut by hedgerows and shell-pocked hooches, Nhi Ha was located on the main infiltration route from North Vietnam to South Vietnam. Private Barker's company could not see the North Vietnamese Army troops dug in and waiting behind the hedgerows. The initial shockwave of enemy artillery and automatic weapons fire devastated Private Barker's platoon. He was killed by the first artillery shell to impact among the American troops. It was later determined that elements of the 4th Battalion, 270th Independent North Vietnamese Army Regiment were defending Nhi Ha at that time.