The 13-gun salute shook the air, releasing a series of cannon booms that instantly conferred a special status on the burial Thursday of Maj. Gen. Harold J. Greene, the highest-ranking U.S. service member killed in a combat zone since the Vietnam War. The remains of Greene, a two-star general, were carried in a caisson, escorted by two platoons, a band and a riderless horse, protocol for those with ranks of colonel and higher.

And when the bugler played taps, the general’s wife, retired Army Col. Susan Myers, and daughter Amelia Greene kept their hands down, while his son, 1st Lt. Matthew Greene, a recent West Point graduate, held his right hand in a firm salute.

More than 100 mourners gathered in Section 60, home to the fallen of the Iraq and Afghanistan wars, to say farewell to the man everyone always called Harry.

Greene, 55, deputy commanding general of the Combined Security Transition Command-Afghanistan, was killed Aug. 5 at an Afghan military academy near Kabul by a man believed to be an Afghan soldier — an insider attack that sent shockwaves through the U.S. military. The assailant wounded15 other military personnel, including eight Americans, before he was killed by Afghan security forces.

Col. Keith Hauck, the Army’s director of materiel, said the day after news broke that Greene was killed, he roamed his office’s cubicles, checking in on about 160 grieving employees, many of whom used to work for Greene five years ago when he was their boss.

Gen. Harold J. Greene (US Army)

“They were devastated,” Hauck said. “They were crushed. They were in tears.”

Greene spent much of the last part of his career deciding what the Army needed during war — helicopters, trucks, tanks, rifles, radios, computers, and so on. That meant Greene also had to decide what was not essential, which also meant he had to disappoint people routinely.

“Harry understood that people don’t mind being told ‘No,’ provided that someone takes the time to explain the reasons why,” Hauck said. “It sounds simple, but in the military, sometimes people don’t take the time to do it. I never once saw Harry Greene not take the time to do it.”

He was the kind of officer who earned his promotions with ease, his friends said, but he was never the type who relished the superiority that came with his standing.

Rick Webster, a Herndon defense contractor and retired Navy officer, was part of a big crowd of friends and colleagues who attended Greene’s promotion to two-star general.

“The reception line went on for hours,” recalled Webster, 56, who went to high school with Greene in Guilderland, N.Y. “People stood in line for a long time to congratulate him, and every person he’d meet, he’d shake their hands vigorously and laugh. He gave everyone time. He just didn’t move them along. He made people feel valued.”

Laurie Buckhout, a retired Army colonel, said Greene served as her mentor at the Pentagon, but that never stopped her from occasionally teasing him about his rank.

“One day, he was wearing his special general’s black leather belt, and I said, ‘Look at you with that belt!’ ” Buckhout recalled. “He looked down and said, ‘You know, I don’t wear it that often. It freaks me out.’ He was that kind of person. Never put on airs.”

Greene, she said, looked out for her when she first joined the Army staff in the mid-2000s. She was trying to bolster the Army’s electronic warfare initiatives — jamming enemy radio signals for roadside bombs, communication signals and radar detection — and needed his help beefing up her programs.

“I was trying to figure out how to get electronic warfare systems in the field in a hurry. We had a hard time making the Army think differently, so I asked him, ‘How do we get this institutionalized across the Army? How do we get the funding? The equipment?’ ” Buckhout recalled. “As soon as I explained the problem, flares went up . . . I walked away feeling like I had a big brother.”

Greene, who became an Army officer in 1980 after graduating from Rensselaer Polytechnic Institute, clearly loved staying in touch with friends. He was active on Facebook, where he posted a photograph of his daughter, Amelia, at a Boston Red Sox game, and one of his son, Matthew, sleeping in bed.

His children and wife were present for the return of Greene’s remains at Dover Air Force Base in Delaware on Aug. 7. Shortly afterward, his son told CNN that he and his dad talked about the risks of serving abroad, especially when the younger Greene decided to enroll at the U.S. Military Academy at West Point.

“There is always that risk that you may have to sacrifice for the greater good of the United States, and that was something we always talked about, and it was something that he was very adamant and proud about that he was able to do that,” the son said.

In Afghanistan, Greene was a key figure in the effort to train Afghan troops to defend their country against insurgents. He was killed at the Marshal Fahim National Defense University, which U.S. military officials have described as the West Point of Afghanistan. A spokesman for the Afghan Defense Ministry described the attacker as “a terrorist dressed in an Afghan army uniform.”

But the mystery that still surrounds Greene’s death makes his loss harder to comprehend, Webster, the retired Navy officer, said.

“Most of us probably figure that a general is safer than many other junior people, but there’s a lot of trouble over there. Anything can happen,” he said. “But Harry would tell you that when anyone is struck down, he’d value everyone’s death, regardless of how senior they were. It’s just that this time, it stands out to the rest of us because he was so senior. But it really isn’t any different.”