Joop WIllJoop Will, 82, was 10 years old in 1943 when the Nazis seized his father Peter, who was never seen again

BERLIN (AP) — Joop Will was only 10 years old when his father, Peter, was seized by the Nazis for being a member of the Dutch resistance.

Will never saw his father again after the December 1943 arrest, but thanks to a series of fortunate coincidences and a newly online Holocaust-era archive, the 82-year-old has finally received his father’s last letter, written to his wife and six sons as he prepared to be deported to a concentration camp in Germany.

“I’ve now been away from you at home for the 42nd Sunday,” the father wrote, counting time by the days of worship missed with his family.

“It is very emotional, he thought of us, he had concerns for us, and now we have the letter that he had in his hand,” Will told The Associated Press in a telephone interview from his home near Amsterdam, his voice quavering.

“To know his thoughts were with us, that is a very emotional thing.”

The letter, handwritten in pencil on two sides of a small piece of paper, was folded into Peter Will’s wallet along with family photos and was recovered by the British army when it liberated the Neuengamme concentration camp in northern Germany in 1945.

It was transferred in 1963 to the International Tracing Service in the German town of Bad Arolsen, which was established by Western Allies in the final days of World War II and initially run by the Red Cross to help uncover the fates of Holocaust victims and others. In 2007, scholars and researchers were allowed access to the documents, beginning the archive’s transformation from a tracing service to a research institution.

The Will family contacted the ITS to see if they had any details on Peter, who died in April 1945 as the Nazis were moving him by train to another camp, but his effects had accidentally been filed under the name of Will’s wife — possibly taken from a letter from her to him that was also in the wallet — and they were told there was nothing in the archive.

But in October, the ITS began putting its archive online, and Peter Will’s belongings were among the 50,000 images initially posted, of some 30 million documents and images in its collection.

A Dutch woman unknown to Will happened to see a news report on the effort and went online to try and track her own relatives’ records, and came across the images of Peter Will’s effects. She decided to track town the Will family, and Joop and his two surviving brothers were stunned by her discovery.

“I was only 10 when my father was arrested but even after such a long time one never forgets,” he said. “He’s always been in my thoughts.”

Peter Will, a Nijmegen meat inspector, joined the Dutch resistance after the Nazis overran his country in 1940, distributing the forbidden newspaper Trouw, and hiding downed Allied pilots in a slaughterhouse shed and helping them escape.

Arrested by the Nazis in 1943, he was handed over to the SS’s intelligence agency, the SD, and taken to a transit camp in Amersfoort, Netherlands, in May 1944.

He was able to communicate by mail with his family from the camp, but on Sept. 17, 1944, upon learning he was to be taken to a concentration camp in Germany, he wrote what would be his last letter. It was never sent.

Unknown to Will at the time, it was the same day Allied troops were being dropped by parachute into the Netherlands in “Operation Market Garden” — immortalized in the film “A Bridge Too Far” — and Nijmegen and Will’s family would be liberated in the coming days.

The Allied attack actually delayed Peter Will’s deportation, but he was shipped a month later to a satellite camp of Neuengamme in Germany and forced into slave labor. As the Allies closed in he was put on a train in April 1945 to be taken to another camp. He died on board and was buried in a mass grave near the town of Brillit, between Bremen and Hamburg in northern Germany.

The family has decided to keep the contents of the letter private — for their own memories alone. But Will gave a glimpse into his emotional words.

“He wrote that ‘I’ve now been away from you at home for the 42nd Sunday,’” Will said. “He didn’t talk about days or weeks, he talked about Sundays — he was a man of deep belief, and in the letter he talked about his beliefs.”

Will and one of his brothers traveled to Bad Arolsen to pick up the effects earlier this month from ITS. With the letter back in the family’s possession, they’re now trying to decide how to best preserve it.

“We’re looking for a place where we can best keep it for his grandchildren,” Will said.

Copyright 2015 The Associated Press.