(CNN) Gretchen Wronka and Martin Hintz had spent more than 60 years thinking their father, an Army pilot, was buried in Italy after he died in a plane crash during World War II.

Then a group of Italian archaeologists told them they were going to look for more of their father's remains.

The siblings were shocked and confused. They had never met their father. Wronka was just over a year old when her father passed away April 21, 1945, and Hintz wasn't born until June 1.

As far as they knew their dad, U.S. Army pilot 1st Lt. Loren Hintz , was laid to rest in Italy after his aircraft came under fire by German forces. He crashed at a farm outside Bagnarola, Italy, just south of Florence.

"We always knew our father was buried in the Florence American Cemetery ," Wronka, now 75, said. "So the mystery of where he was, we thought he was there."

Gretchen Wronka embraces her grandson after he read a portion of her father's autobiography during the memorial ceremony.

All those years ago, Loren Hintz's partially recovered remains were buried at his family's request with those of nearly 4,400 other American veterans at the cemetery south of Florence. But then, about seven years ago, a group of archaeologists started a journey to find the rest of his remains.

After years of exploration and excavation, new bones were found -- along with part of Hintz's plane -- in a little Italian farm field.

Now, 74 years after his death, Loren Hintz's complete remains were finally buried Saturday at the Florence American Cemetery.

"I have a great sense of peace and fulfillment," Wronka said after the ceremony. "It's been a long journey, and the preparations have been detailed and extraordinary."

They got to know their father through his belongings

Loren Hintz grew up on an Iowa farm, Wronka said of her father. He enlisted in 1941, before Pearl Harbor, and was excited to join the Army Air Corps.

"He had a passion for adventure. He was a young man who wrote poetry," said Wronka, who lives in Minnesota. "He loved to travel. He had a great zest for life, and this came through as children for Martin and me."

First Lt. Loren Hintz enlisted as a U.S. Army pilot in 1941, before Pearl Harbor.

Martin Hintz, 73, said that as kids, they would often go up to the attic of their family home and look through their father's chest, which held his uniform, books and other personal items. They tried to get to know their father through the surviving items they had.

"We knew him, but we never met him," said Martin Hintz, who lives in Wisconsin. "Several years ago, we finally got to meet him when the site was excavated, after many years of searching."

It took a community to find his remains

Nearly 20 years ago, the siblings started looking for and asking about their father.

Wronka commented on a website for P-47 Thunderbolt aircraft, the kind her father was flying when he crashed. A man responded that he knew her father, and that sparked the family's quest for more information.

After asking questions and searching for answers, they received an email in 2012 from Piero Fabbri, an aviator and amateur archaeologist living in Bologna, Italy. That email was the start of a long journey to come.

A group of Fabbri's friends had made a list of American air troops who had gone down near Bagnarola. Loren Hintz was a name on the list.

"It's rather uncanny to be receiving an email from a complete stranger half a world away," Hans Wronka, Loren Hintz's grandson, said.

The group began to research Loren Hintz and start their search, but they had little success during the first year. Their luck turned around when they found people who remembered the day of the crash.

With their help, archaeologists pinpointed a location of the crash, and they found a large piece of metal 16 feet under the ground. That's where the search began.

In 2016, archaeologists started digging in a little field with a backhoe. Pieces of machines and artifacts were slowly uncovered. People started to gather as small pieces turned to larger ones the deeper they dug.

Then the smell of oil filled the air. They had found the engine of the P-47, the aircraft Loren Hintz had flown. Everything around it was covered in oil, even the surrounding soil.

"It was just an incredible, tangible symbol when you saw what the force of that crash had done to a huge, huge powerful engine," Wronka said. "After that, there was almost a silence because when you find an engine, you know that behind the engine, there was a cockpit."

Slowly, the archaeologists started to dig by hand. They were pulling up smaller artifacts. Then they found a small item: the dog tag of Loren Hintz.

The site where Loren Hintz's initial remains were buried.

The work got slower and more painstaking. Everyone working at the site knew they could soon find Loren Hintz's remains. They even called a priest to the site. Suddenly everything went silent. The family was called over.

On July 23, 2016, they finally met their father.

"There were laying the bones of our father," Gretchen Wronka said. "They were smooth and beautiful. The entire crowd was filled in silence. It continues to amaze us. People were weeping. It was incredible."

Finally laid to rest

It took three years for Loren Hintz's additional remains to be interred.

After the remains were found in 2016, the family worked with the American Battle Monuments Commission and the Defense POW/MIA Accounting Agency to identify and confirm they belonged to Loren Hintz. DNA testing proved it.

The family was amazed to learn how their story united so many people who were interested in their father. They know their story mirrors those of thousands of military families who have lost loved ones and searched endlessly for answers.

"We are so honored to have this opportunity to have a memorial service and to bury our father," Gretchen Wronka said. "There are over 4,000 other soldiers buried here. We are hoping we can symbolize so many families."

Master Sgts. Ernesto G. Gonzalez and Daniel Davenport carry the flag-draped burial box of 1st Lt. Loren Hintz that was interred in his original grave.

More than 70 years ago, Loren Hintz's partially recovered remains were buried at the Florence American Cemetery alongside his fallen brothers-in-arms at his family's request. On Saturday, the newly found remains were laid to rest. His whole family was there to honor him -- children, grandchildren and great-grandchildren all played a role in the ceremony.

"It was a lovely day to be surrounded by my sons, grandchildren, my brother and his family," Wronka said. "I know my parents would've been so pleased and so proud and so grateful too."

For them, the interment puts to rest a years-long journey.

Now, they find peace knowing their father is resting and his legacy will live on for the many people around the world who were part of finding and honoring Loren Hintz.

"This is the legacy my father has left, this is the legacy we are passing on to the next generation," Wronka said after the ceremony. "They are strong, they are proud and they are Americans, and they know that a part of them is in this cemetery. I think that this next generation, even the little ones, will grow up knowing they were a part of this."