Death of Two-Star Army General Harold Greene a Rare Killing

Image: Afghan National Army soldier keeps watch at gate of a British-run military training academy Camp Qargha, in Kabul

An Afghan National Army (ANA) soldier keeps watch at the gate of a British-run military training academy Camp Qargha, in Kabul August 5, 2014. The U.S.-led coalition in Afghanistan said there had been "an incident" between Afghan and foreign troops at a British-run military training academy in Kabul on Tuesday, and sources added that casualties were feared. OMAR SOBHANI / Reuters

The death of U.S. Army Major Gen. Harold Greene on Tuesday not only marks the highest-ranking casualty in the Afghanistan conflict — it’s also the first time an Army officer with a major general rank or higher has been killed by enemy fire overseas since Vietnam.

The last time was in May 1970 — when Major Gen. John Dillard Jr. was shot down while flying a helicopter over central Vietnam, according to Department of Defense data. At that point, Dillard, 50, had become the sixth American general to die in the line of fire during the Vietnam War.

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About 2,340 Americans have been killed in combat in Afghanistan since coalition forces landed in 2001, but the death of Greene — a two-star general — is a rarity. A lone Afghan gunman is accused of ambushing more than a dozen Western soldiers who were visiting the Afghanistan National Military Academy in Kabul. Also wounded in the attack were a German brigadier general and several Americans.

The gunman was killed after spraying his automatic weapon from a window, according to an Afghan intelligence source. He was dressed in Afghan military clothing, and the attack appeared to be an example of so-called “green-on-blue” — when Afghan soldiers or police turn their weapons on coalition troops.

A retired army general in Afghanistan told NBC News that high-ranking generals regularly travel outside the bases, so it’s “amazing to me that we haven’t lost someone until now.”

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Before this latest incident, only one other general has died while serving in either the war in Iraq or Afghanistan: Brig. Gen. Terence Hildner — a one-star general from Fairfax County, Virginia — died of natural causes in February 2012 while in Kabul. His family said the 49-year-old father of four likely suffered a heart attack in his room.

During 9/11, a three-star general — Army Lt. Gen. Timothy Maude — was killed during the attack on the Pentagon. His death was the last time enemy combatants killed an American general on home soil.

Courtney Kube and Donna Mendell of NBC News contributed to this story.