Growing up in the 1960s in New York City and Connecticut, Liz Perle, who later worked in the publishing industry here, heard some vague stories about her grandparents’ exploits in Europe the year before World War II broke out.

“She knew they had done something to save some Jews in the 1930s,” says her husband, Steven Pressman, a onetime print journalist who lives in San Francisco.

It wasn’t until an unpublished memoir Eleanor Kraus had written and stuck in a drawer turned up after her death in 1989 that her family realized what she and her husband Gilbert had done: residents of Philadelphia, the Krauses had brought 50 Jewish children from Vienna to the United States on the eve of the war in a personal rescue mission, with the backing of the Philadelphia-based Brith Sholom fraternal organization. They faced opposition from the leaders of Philadelphia’s Jewish community, restrictive American immigration legislation, and a total lack of expertise in international rescue efforts.

The Krauses’ initiative, which saved the children’s lives, remained a largely unknown and untold story of the Holocaust — until Pressman, now a self-taught, rookie documentary filmmaker, decided to tell the story of his grandparents-in-law, both of whom died before he and Liz met.

The result, “50 Children: The Rescue Mission of Mr. and Mrs. Kraus,” premieres this week, geared to Yom HaShoah, on HBO. The hour-long documentary (with narration by actors Alan Alda and Mamie Gummer) features old photos of the couple, “cinematic touches” that capture the flavor of their work in Vienna and Berlin, and interviews conducted with many of the rescued children (ages 5 to 14 in 1939; now senior citizens), in Israel and several cities around the U.S. It’s a story of bravery, of bureaucracy overcome, of anti-Semitism that kept the Krauses’ local Jewish community from backing their effort, of farsighted Jewish parents who entrusted their children to a pair of American strangers, of some children who never saw their parents again.

The documentary shows how the Krauses, a totally secular Jewish couple, worked with Brith Sholom, in which Gilbert Kraus was an active member, to take in endangered children at the organization’s summer camp that had 50 open spaces; how they persuaded their friends to sign sponsoring affidavits to bring the children to the States; how they traveled to Nazi Europe (Austria had recently been annexed by Germany) to personally interview and choose the lucky children, and escort them to freedom.

The 50 were, Pressman says in a telephone interview from the family’s home in San Francisco, “the single largest group of [Jewish] children” to come to the U.S. from Nazi Europe “at one time during the Holocaust.” Because of the Krauses, he says, “thousands” of people in the children’s families, including children and grandchildren and other relatives, are alive today.

First Gilbert, an attorney, angered by the reports of a growing threat to Jews in Germany and Austria, decided to act; he traveled, accompanied by Dr. Robert Schless, a German-speaking Jewish pediatrician from Philadelphia, to Europe. Then he persuaded his wife to join him; leaving their two children in the hands of close friends; with war imminent, the rescue mission was too much work for Gilbert and his friends to do by themselves, he told Eleanor.

Their several weeks in Berlin and Vienna, the documentary shows, were a bewildering mix of glamour (they stayed at first-class hotels and frequented fashionable restaurants), intrigue (they were undoubtedly watched by the SS), and hard work (they made the rounds of embassies and Nazi bureaucracy).

Eleanor, Pressman says, was, reasonably, “pretty terrified” of going into the lion’s den; Gilbert probably wasn’t. “There wasn’t a whole lot that was going to scare Gilbert Kraus.” The more that people said he couldn’t save the children, the more determined he became. “Gilbert Kraus was one stubborn son-of-a-bitch.”

Back in Philadelphia, Gilbert thought about mounting a second rescue effort, Pressman says, but the war started and “the gates closed.”

Gilbert Kraus died in 1975.

During the documentary’s two-year production process, Pressman tracked down the now-aged children, most of whom had lost touch with the Krauses after going to live in foster homes or with relatives in this country. Pressman was unable to trace all the children; the women who had married had changed their last names.

He made the documentary with a budget “in the low six figures” with the financial support of private donors, foundations and an Austrian government fund. The most common reaction when he approached possible donors for funding: “Not another Holocaust film!”

“All Jews,” Pressman says of them.

He stressed that he wasn’t making “a typical Holocaust film. Not a single image of concentration camps is in this film. It’s a story of one American couple.” A story with plenty of historical and political context. “I didn’t want to tell just a small, personal story.”

The Krauses, who never talked about what they had done, returned, apparently unchanged, to their lives in Philadelphia, Pressman says.

“They were totally non-religious — not an inkling of Judaism in their home,” says Robert Braun, one of the rescued children, who, with his sister Johanna, lived with the Kraus family for two years after leaving Austria. Now 84, a retired dentist living in Fairfield, Conn., he says the Krauses celebrated Christmas, had a Christmas tree in their home, sent their children, and the two Jewish kids from Vienna, to a Quaker school.

What had made the Krauses trade their comfortable lives in the States for the dangers of Nazi Europe? “They felt it was an outrage that nothing was being done” by the wider Jewish community or the US government to rescue endangered Jews, says Braun, who appears in the documentary.

Did he consider the Krauses heroes?

“Not at the time,” he says. When living in the Kraus home, he and his sister simply considered Gilbert and Eleanor ersatz parents (his own parents survived the war, and continued to live in Vienna). “In retrospect, very much so.”

The Krauses, Pressman says, were “ordinary people” who did “extraordinary” deeds.

Do Pressman and Perle’s two children know what their great-grandparents did in 1939?

Certainly, Pressman says. Now college-aged, they followed the progress of their father’s documentary and heard of the Krauses’ exploits. “They know everything about the story. Ordinary people have the power to become extraordinary heroes. I don’t think Gilbert and Eleanor Kraus set out to be heroes. But looking back, that’s exactly what they became.”

“50 Children” will premiere on HBO on Monday, April 8 at 9 p.m.

steve@jewishweek.org