The last time Daniel Dien Luong saw his father was through the fence of a former army barracks in southern Vietnam more than 30 years ago.
His father was being held prisoner by the Communist government, which had arrested thousands of former military personnel to be "re-educated" after the Vietnam War.
The 13-year-old rode his bike two hours to visit his father every Saturday afternoon at 1 p.m. They waved at each other from afar as armed guards stood watch.
One day, the family discovered the barracks empty. It was two months before they received a letter from Luong Van Hoa, about 1,000 miles north of their home in Saigon, now known as Ho Chi Minh City.
In 1977, the letters stopped. The family feared the worst. A death certificate came 10 months later.
Luong, like hundreds of family members of captured South Vietnamese soldiers, has struggled to find out where his father is buried.
Next month, Luong and his mother will travel to Yen Bai province in hopes of recovering his father's remains, 32 years after his death.
They are able to do so with the help of a former South Vietnamese army major who heads a nonprofit called the Returning Casualty that has located and identified unclaimed graves of those who died in the prison camps.
Luong, now 46 and living in Los Angeles, said that finding even a trace of his father would bring closure to his family. In the Vietnamese Buddhist tradition, without a proper burial the spirit is lost, forever wandering.
"For my dad, he never had the chance to come home," Luong said. "His spirit could not come with us. There was always this sense of uncertainty."
Since 2007, the Returning Casualty has located 313 graves and led 59 families, mostly from the U.S., through thick forests to find the remains of their loved ones, said Thanh Dac Nguyen, who heads the Houston-based organization.
Uncovering and identifying graves is not an easy task, he said. Most are unmarked or the gravestones are illegible. Often the land has been abandoned and overrun with weeds.
For his searches, Nguyen relies on local residents and hand-drawn maps for clues. He also has worked to obtain burial records from local officials.
Like thousands of his fellow soldiers, Nguyen was thrown into a "re-education" camp at the end of the war. Prisoners were forced into hard labor and suffered from hunger, dehydration and poor sanitation. Many did not survive, and their families never knew what happened to them.
Nguyen was one of the lucky ones. He returned to his family nine years later and eventually immigrated to Houston. But he never forgot about his former comrades who died in internment. He felt it was his duty to bring peace to their families.
In 2006, he began researching how to locate the graves. He worked with the Vietnamese government to secure permits to exhume the graves and search for family members. His organization relies on donations to help pay for the trips.
For years, Luong and his mother, Nhung Thi Nguyen, 64, had talked of finding his father's grave site. But they didn't know where to begin.
A few months ago, she received a call from a friend who had read an article about the Returning Casualty in a Vietnamese language newspaper. There was her husband's name — Luong Van Hoa, buried in the town of Thac Ba, surrounded by 30 other graves.
Waves of sadness washed over her. Her son was also stunned; it had been so long since he'd seen his father's name.
Luong and his mother made plans to travel to northern Vietnam with the Returning Casualty. Ten other families will do the same, Nguyen said.
As a teenager, Luong wanted to be in the army like his father. "I think he planned for that too," Luong said. "If he survived, I would imagine that we could go down to our plot of land and be best friends."
But fate would take Luong's life on another course.
The war had been difficult for the family. Luong's 3-year-old sister died in artillery fire when the family visited his father one day.
The Luongs had missed an opportunity to escape Vietnam immediately after the Communist takeover in 1975. Luong's father decided to stay behind because he did not want to leave his mother. He believed he would be safe, but was taken to the prison camp shortly after.
After Nhung Thi Nguyen discovered that her 39-year-old husband had died, she took her three children and boarded a boat headed for the open seas. The family eventually immigrated to Glendale.
Luong became a computer programmer. As the oldest child, he has the strongest memories of his father — a man who showed him soldier's food rations, who helped him build a model house for a school project.