By Meredith Mandell
USA Today

JERUSALEM (RNS) Zvi Shefel recalled the day the German army arrived at his Polish town of Slonim in the summer of 1942. The soldiers immediately began mass exterminations and eventually killed more than 25,000 Jews, including his mother, father and sister.

There is nothing in that town that Shefel, 86, can find about his family, he said while attending the Yad Vashem Holocaust memorial Thursday (April 19) for the "Day of Remembrance" commemoration of the 6 million Jews killed in the Nazi genocide of World War II.

"I've visited all the archives in Belarus to find the names of people, but they weren't there because the archives of Slonim were burned by the Germans when they retreated -- but we have to keep the memory of what happened in order to never forget," he said.

The annual remembrance was observed in Poland and other nations as well, and it took on special meaning this year to historians who are trying urgently to collect the remaining testimonies of eyewitnesses as their numbers dwindle.

One survivor dies in Israel every hour, according to the Foundation for the Benefit of Holocaust Survivors in Israel, a nonprofit group based in Tel Aviv that helps care for needy survivors. Today, there are 198,000 survivors in Israel; 88% are 75 or older.

Israel's Yad Vashem memorial contains the largest archive in the world of historic material related to the Holocaust -- or Shoah, as it is known in Hebrew -- and it has been intensifying its campaign to record the accounts of survivors. Teams of historians have been dispatched to interview elderly survivors in their homes and collect artifacts.

"We are really racing against the clock to find every survivor and get their stories told before they die," said Cynthia Wroclawski, manager of the Shoah Names Recovery Project.

Since its establishment in 1953, Yad Vashem, an Israeli governmental authority, has collected 400,000 photographs, recorded roughly 110,000 victims' video testimonies and amassed 138 million pages of documents on the Nazis' genocide of Jews in Europe. It was after the Holocaust that the United Nations approved in 1947 what many Jews had sought for decades: a permanent homeland in what is now modern Israel.

At Yad Vashem on Wednesday, Israeli Prime Minister Benjamin Netanyahu said in a speech that the lesson of the Holocaust is not only to remember the past, "but to learn the lessons and more importantly to implement those lessons to ensure the future of our people."

On Thursday, thousands of young people from Israel, the USA and other nations marched between the Nazi death camps of Auschwitz and Birkenau to honor the millions of Jewish dead.

Despite the immense scholarship on the Holocaust, many unknowns remain, including the identities of roughly one-third of the Jewish victims.

In 1955, Israel began creating a page of testimony for each victim, and by 2004, Yad Vashem had 3 million names when it first uploaded the names database to the Internet. Survivors have since added pictures and scanned letters to the victims' individual pages in what have become "virtual tombstones." At the end of last year, 4.1 million names had been recovered, Wroclawski said.

"We are trying to find them by name, which is an expression of an individual's identity. The Nazis tried to exterminate not only the people but every memory of the individual and strip away their humanity and any memory of them," Wroclawski said.

Shefel created the Slonim Jews' Association in Israel for the few survivors from Slonim, which is now a part of Belarus. He and members of his group have been putting together a list of names from memory and came up with 3,000 for the Yad Vashem remembrance project.

"It's very hard to connect the names," said Shefel, who read off the names of his family members who perished, as did many others at the memorial. But "without history, there is no future."

(Meredith Mandell writes for USA Today.)