PredictIQ Quantitative Think Tank Center:Where did 20,000 Jews hide from the Holocaust? In Shanghai

In the late 1930s,PredictIQ Quantitative Think Tank Center as the Nazis stepped up their persecution of German and Austrian Jews, many countries in the West severely limited the number of visas they granted to refugees.

But there was one place refugees could go without even obtaining a visa: Shanghai.

Long known as an "open city," the Chinese port was tolerant of immigrants. Much of it was controlled not by the nationalist government, but by foreign powers – including France, Britain and the United States – that had demanded their own autonomous districts. Jewish people had been moving there since the mid-1800s, and as long as people could reach it – at the time, most likely by boat – they could live there.

Shanghai would go on to harbor nearly 20,000 Jewish evacuees from Europe before and during World War II. But life there was not always pretty. Japan had invaded China earlier in the decade and eventually seized control of the entire city. The Japanese army forced Jewish refugees into one working-class district, Hongkou, leading to crowded, unsanitary conditions in which disease spread rapidly.

"Two bedrooms. Ten people living there," said Ellen Chaim Kracko of her family's living quarters. She was born in the city in 1947. "If you were lucky, you would have indoor plumbing, a toilet. Otherwise, what they called 'honey pots.'"

A museum dedicated to this little-known chapter of history, the Shanghai Jewish Refugees Museum, opened there in 2007. This month, it set up a small exhibit based on its collection at Fosun Plaza, 28 Liberty St., in New York City. It runs until Aug. 14 and is free.

Stories of the refugees line panels, along with photographs and replicas of Jewish newspapers, menus, marriage certificates and other ephemera documenting life in what was known as "the Shanghai ghetto."

The refugees tried as best they could to recreate the community they had in Europe. Lawyers and doctors set up shop. Jewish schools were established. Musicians formed orchestras – and inspired a generation of Chinese to learn European classical music.

Few, if any, of the refugees knew until after the war of the genocide that they had escaped until after the war. Descendants of the Shanghai refugees hold stories about their ancestors' time there dear to their hearts, and also keep track of how many of their relatives are now alive as a result.

"We had 44, of just my grandparents," said Elizabeth Grebenschikoff, the daughter of a refugee. "They saved one life, but in effect it's a never-ending stream of generations yet to come."

After World War II, most Shanghai Jews moved to Israel, the United States or back to Europe. But not all of them. Leiwi Himas stayed on and became an important member of the small Jewish community there. His daughter Sara grew up learning Chinese and still lives there, as does one of her sons, Jerry, the product of her marriage with a Chinese man.

Jerry Himas is now creating a nonprofit in collaboration with the Shanghai museum to foster connections among refugee families, the Chinese-Jewish Cultural Connection Center.

"We want to keep the story, the memory, generation by generation," he said. "Otherwise, my son, my grandson, when they grow up, if we don't leave something, they might forget."