QUANG NGAI PROVINCE, Vietnam -- The day Sgt. 1st Class Tommy Murphy died is still ingrained in his daughter's mind.

It was April 7, 2001, and Tycoria Johnson was just 9 years old. On that Saturday, Murphy, along with six other American service members and nine Vietnamese counterparts, departed on an MI-17 helicopter to investigate a potential recovery site.

They were part of a Defense POW/MIA Accounting Agency mission in search of the remains of fallen service members from the Vietnam War. Her father was a team sergeant, she said, who supervised and did much of the planning for the team.

But as the weather worsened, the helicopter veered off course and collided into a mountain hidden by clouds in central Vietnam. No one survived.

IN HER FATHER'S FOOTSTEPS

Johnson, now a senior Airman based in Japan, recently volunteered for a joint mission with DPAA, where her father once worked as a mortuary affairs specialist.

"He would talk about his missions a lot," she said, recalling the videos he would show her of people digging at excavation sites. "I knew that he enjoyed it and I think he would be surprised that I actually signed up to do it."

With her skills as a radio communications operator in the Air Force, Johnson was sent to Quang Ngai Province -- not far from her father's crash site -- to augment a recovery team.

Atop a small mountain covered in a thick jungle, the team's goal was to find a Marine pilot lost after his A-4E Skyhawk attack jet had crashed there during the war.

"You feel that you're a part of something bigger [than yourself]," she said at the excavation site in mid-March.

For about a month, her team lived in tents lifted slightly above muddy, rocky terrain on plywood platforms. The humid heat stifled the air as insects and dangerous creatures, such as snakes and scorpions, lurked nearby.

Each day, team members climbed 700 feet in elevation along a half-mile trail back up to the site.

While it can take months, even years, to find remains that lead to the identification of a missing service member at these sites, team members understand why they still do it.

"Speaking from experience, you want to have something of your family member," Johnson, 26, of Prince George, Virginia, said. "Just having someone take the time and search for them also shows that the military cares for [them] as a human being."

SEARCHING FOR CLOSURE

Sgt. 1st Class Zachary Plante, the mountaineering expert on Johnson's team, spoke of the deadly encounters his unit saw in Operation Hammer Down while deployed to Afghanistan with the 25th Infantry Division.

The air assault offensive in June 2011 was supposed to last about a day, he said, but it turned into a weeklong battle with Taliban fighters.

While some of his fellow Soldiers did not make it out alive, they did return home, even if in a flag-draped coffin to comfort mourning friends and family.

In his fourth recovery mission with DPAA, Plante said those memories continue to motivate him to recover as many Americans as possible. In Vietnam, there are more than 1,200 still missing.

"We all lost people downrange, but we saw them come home," Plante, 40, of Orange, Massachusetts, said.

Similar events also weigh on Sgt. 1st Class Christopher Krogman, the team sergeant, who has deployed five times and lost Soldiers in combat.

"It's always hard losing a service member, but by bringing them back we were able to have closure immediately," Krogman, 35, Bend, Oregon, said. "With these [missing] service members, the units never really had closure."

Living in the middle of a jungle surrounded by mountains also gave team members a new appreciation for what Vietnam War-era troops endured in their fighting.

"A lot of the terrain we've been in, I can't imagine moving through it," said Plante, a former mountaineering instructor at the Army Ranger School. "They were in the thick of it."

For the most part, the team looked past the uncomfortable times and to the overall purpose of the mission.

"You can do anything for 30 days, regardless of how bad the conditions are, you can do it," Krogman said. "We harp that from the very beginning and they adopt that."

CRASH ANNIVERSARY

Johnson needed perhaps the least convincing to drive on with the mission.

"I feel like I'm completing what he started," she said of her father. "It pushes me to keep going, especially with the hike. It's not an easy job, but it is rewarding."

When her father and the 15 others died in that helicopter crash, it had a devastating ripple effect across the entire agency, where many of them worked.

Both the incoming and outgoing commanders for the detachment in Vietnam were also on the helicopter.

"It was absolutely terrible," said Johnie Webb, the agency's deputy of outreach and communications. "You never want to lose anybody, but here we are trying to recover those guys who lost their lives in the Vietnam War and we lose more of our guys."

At the time, a recovery team in Laos was about to leave the country when DPAA officials asked some of them to divert to Vietnam and help recover the bodies of their fellow team members.

"We got more than we needed," Webb said of the volunteers. "We brought our guys back home and did the autopsy and identification at our facility [in Hawaii]."

Webb said Johnson's father was one of his good friends. He recalled that he and others in the office nicknamed him "gentle giant" because of his muscular frame.

"I'd known Tommy for many years," said Webb, who has spent four decades at the agency. "One of the things about his [military occupational specialty], which is now 92M, is that it's a very small MOS."

Before Johnson left for Vietnam, Webb had the chance to speak with her at the agency's headquarters in Hawaii.

"I'm impressed with her," he said from his office. "She told me, 'Well, that's where my dad lost his life, so I need to go over there and see for myself what it is like.' He would have been proud of her."

Johnson plans to attend a memorial ceremony Saturday at the crash site, where a plaque is now on display honoring those who were killed, including her father.