BAD AROLSEN, Germany — A mother and child separated. A father's war wound. An uncle's name on a list.

The unrelated and disparate items are among the discoveries made by 40 Jewish genealogists who spent the past week plumbing a trove of Nazi documents made public after 60 years.

For genealogists of Jewish families, the Holocaust is both a tragedy and a black hole, because so many of the 6 million Jewish victims disappeared without a trace. For years, researchers hoping to fill the gaps have longed to dive into the more than 50 million documents held in this German spa town and entrusted to the International Tracing Service, or ITS.

"The Nazis took away our names and gave us numbers. Our role is to take away the numbers and give back the names," Gary Mokotoff, a genealogist who helped organize the group from Israel, the U.S., Britain and Australia, said Thursday. "There is a wealth of information here."

For decades after World War II, the files were used only to help find missing persons or document atrocities to support compensation claims. But in November, the last of the 11 countries that govern the archive under the auspices of the International Committee of the Red Cross cleared the way for public access.

Since then, interest has skyrocketed. Erich Oetiker, deputy director of the archive, said while the staff of 400 continue to process some 1,000 tracing requests per day, there are now also near-daily visits from historians or individuals eager to trace a lost person's fate or view an original document.

American genealogist Sallyann Sack suspected for years that the collection held answers to questions about her family.

In the 1980s, she put in a request trying to trace the birth parents of her adopted cousin, who had survived Buchenwald as a 9-year-old boy, then been brought by her aunt and uncle to the U.S. A form letter came back saying the search had turned up nothing.

But digging deeper during her time here, Sack was able to cross-reference the birth mother's second given name and access records of search requests made to the ITS since it opened in 1955 — often detailed letters by individuals who reveal nuggets of family history while seeking a missing loved one.

"I found here that his mother, who was separated from him when he was less than 5 years old, also had survived," she said. "She came to the U.S. in the same year that he did, in 1949." The mother, if alive, would be 93 and Sack presumes she is dead. The cousin is in his 70s and still alive, but Sack asked not to identify him.