Her Brother Disappeared in War 80 Years Ago. She Finally Got to Say Goodbye.

When Margery Hop Wong bade her older brother goodbye in 1943, she was just a 12-year-old girl who loved it when he took her for joy rides in his used convertible around the apple orchards their family worked.

Yuen Hop left their home in Sebastopol, Calif., a small town 55 miles north of San Francisco, at 19 to join the U.S. Army. His little sister never saw him again. She knew he had died in the war, but she did not know how. Or where. Or what had happened to his body.

On Friday, Ms. Wong, now 94, sat in the front pew of a mortuary just south of her home in San Francisco, her brother’s remains in a casket draped in an American flag. Younger generations of the Hop family and military veterans filled the rows behind her as a singer led the group in “Amazing Grace.”

For 80 years, Sergeant Hop was lost. Now, he was found.

Ms. Wong was the youngest of seven children born to Gin and Chan Hop, immigrants from China who spoke Cantonese and struggled to communicate with their American-born children, who grew up speaking English.

Life was difficult because of anti-Chinese sentiment fueled by the Chinese Exclusion Act, passed by Congress in 1882 to dramatically restrict Chinese immigration. Chinese immigrants were regularly prohibited from living or working where they wanted, Ms. Wong recalled in an interview. She said her brother was proud to have scraped together money working as a mechanic and drying apples to buy a used convertible and tried to make life fun for his brothers and sisters.

In October 1943, shortly after graduating from high school, Yuen Hop left to fight in World War II, reaching the rank of staff sergeant. Ms. Wong said she and other relatives had worn badges identifying themselves as Chinese during the war so as not to be ordered to report to Japanese internment camps.

In December 1944, Sergeant Hop, a waist gunner in the U.S. Army Air Forces, had been part of a crew on a B-17 plane flying a mission over Bingen, Germany, as part of the Battle of the Bulge, which would be a crucial, yet very deadly, victory for the Allied forces.

The plane was struck by enemy aircraft fire, went up in flames and began spiraling downward. The pilot ordered the men to bail out, and they jumped, deploying their parachutes. Most of them were captured and taken to a German prisoner of war camp. But three of them were never found, including Sergeant Hop.

His family knew he had most likely died, but little else. His parents kept a framed photo of their handsome young son, in his bomber jacket and goggles, above their mantel. But partly because of the mores of their generation and partly because of the language barrier, they rarely talked about him, several relatives said.

“We saw his photo when we visited my grandparents,” Sergeant Hop’s nephew Ronald Hop recalled. “The only thing we knew was that he died.”

After the war, in 1946, the American Graves Registration Command began investigating the sites where planes had crashed in the Bingen air raid. The research included interviewing local residents there, several of whom said they had seen American soldiers land using parachutes — and that one had appeared to be Asian.

But by 1950, the leads had dried up, and Sergeant Hop was officially listed as “non-recoverable” and missing in action. He was awarded numerous posthumous medals including a Purple Heart.

In 2013, the case landed on the desk of Nicole Eilers, a historian with the Department of Defense agency charged with finding missing soldiers. German researchers had found documents referring to a war crimes case that lined up with the outlines of Sergeant Hop’s disappearance.

Slowly, Ms. Eilers and other American and German researchers pieced together that Sergeant Hop and the two other missing soldiers who had jumped from the plane had been captured by German SS troops, the soldiers of the Nazi Party. They were put on a train bound for a P.O.W. camp but were killed before they got there — most likely for trinkets such as jewelry or cigarettes they had on them, Ms. Eilers said.

She visited the area to conduct more research and determined that they had been buried in a mass grave against the wall of a small cemetery in the town of Kamp-Bornhofen. The agency had to persuade the local authorities to allow them to excavate the grave, and they eventually dug up the bodies, which had been buried two to a cloth sack.

Back home, Margery Hop Wong gave DNA via a cheek swab, which matched some of the remains found in the grave. And then it was confirmed. Her brother had been found.

“It’s an incredible moment,” Ms. Eilers said in an interview, her voice cracking, of what it is like to solve a case like this one. “I’m not going to give up on these guys ever.”

The agency aims to find and identify the remains of 200 missing soldiers each year. It is rare that one is of Chinese descent.

Of the more than 16 million Americans who fought in World War II, 20,000 of them were Chinese. Of those, 40 percent were not U.S. citizens, but many of them had enlisted to prove their pride in their adopted country, according to Ed Gor, national director of the Chinese American WWII Veterans Recognition Project. Sergeant Hop was a U.S. citizen by virtue of having been born in California.

Mr. Gor gave Ms. Wong a bronze medal designed to commemorate Chinese veterans and told the younger generations of nieces and nephews at the funeral on Friday that the same DNA that had inspired their uncle to fight for democracy was present in them, too.

Ms. Wong said it was a bittersweet moment to learn what had happened to her brother. His death was violent, and she said she hoped he had not suffered too much. But she was also glad to know that he had been located and that she had been able to give him the burial he deserved.

His name, carved into the Wall of the Missing in a cemetery in France, will be marked with a rosette to signify that his remains have been recovered.

“It took a long time, but we have closure now,” Ms. Wong said, adding that she wished her parents, who died in the early 1970s, had lived long enough to learn their son’s fate. She wished her siblings, all of them gone now, had known, too.

On Jan. 31, an American Airlines plane landed at San Francisco International Airport carrying a casket with Sergeant Hop’s remains. It emerged from the belly of the aircraft, and pallbearers carried it through the rain across the tarmac to a hearse. There, Ms. Wong was reunited with her brother.

On Friday, after speeches and eulogies, a pianist played “America the Beautiful” as scores of people approached the casket, veterans firmly saluting it, and Chinese American friends and relatives bowing toward it three times.

Local police officers on motorcycles shut down Highway 280 as a motorcade wound its way to Golden Gate National Cemetery, where a huge American flag perched on a hill flew at half-staff in Sergeant Hop’s honor.

Soldiers removed the flag from the casket, folded it into a triangle and gave it to Ms. Wong, one kneeling before her to thank her for her brother’s service. Others performed a three-volley salute. A bugler played taps. And then Sergeant Hop’s casket was slowly lowered into the ground in a plot beneath a tree where it will be marked with a marble tombstone.

At last, he was home.