For most Holocaust survivors, coping with life after the war meant forgetting the past, placing the memories of lost people and places in a metaphorical box and leaving it shut. This was what Sala Garncarz did. After five years in seven different labor camps and losing her parents and much of her family to Auschwitz, she too shut those traumatic years away in a box. Except, in her case, the box was a real one, a red-and-white "Spill and Spell" box that once contained a children's game and into which she stuffed every piece of paper that passed through her hands during the war - 300 letters, photographs, postcards and diary entries, a real-time chronicle of her Holocaust experience. In 1991, scheduled to undergo a triple bypass surgery, she broke her nearly 50 years of silence about the box and its contents and presented it to her daughter, Ann. It was immediately clear that the hundreds of yellowed pages of faded scribbling in Polish, Yiddish and German, finally exposed, were much more than just precious family heirlooms. According to Holocaust scholars, Sala Garncarz's letters are a unique, almost archeological, find that offers a highly documented glimpse into the emotional vicissitudes of one survivor's world - as well as further historic details about the Nazi postal service and the extensive network of over 160 labor camps in the Upper Silesia region of Poland, which exploited over 50,000 Jewish slave laborers to build, among other things, a branch of the autobahn. In the exhibit, "Letters to Sala," now at the New York Public Library until June 17, the contents of that secret box are now on display. "It's quite a find. It's even more than quite a find. It's simply extraordinary," said Jill Vexler, the curator of "Letters to Sala" and a cultural anthropologist who has worked on many major Holocaust exhibitions. "It's not only the quantity. As psychologists would say, it's the longitudinal. It's the A to Z. It's from deportation to liberation. It's the whole diachronic pull on this woman's life, from wrenching herself from her mother's arms to her deep, devoted, extraordinary friendship with Ala Gertner [a woman in the same labor camp as Garncarz who would be hung at Auschwitz for her role in the 1945 plot to blow up one of the crematoria], to falling in love, to her profound relationships with the women in the camps." Pinned to the walls of the small, somberly lit exhibit space, the letters and postcards provide a full portrait of Sala Garncarz (now Sala Garncarz Kirschner) from the age of 16 to 21. In the early letters, from her first labor camp, Geppersdorf, to which she was transported after volunteering to take her older sister's place in a forced deportation, she expresses her fear and homesickness. Garncarz wrote to her parents, then still living in the town of Sosnowiec in southwest Poland, describing their parting at the train station: "If you could have looked deep into my heart, you would have seen how desperate I was. Still, I tried to keep a smile on my face as best I could, though my eyes were filled with tears." One of the most remarkable aspects of the letters is their very existence. From 1940 until 1943, even as she moved from one labor camp to another, Garncarz was still able to send and receive letters through the Nazi postal service, placing a Hitler stamp on the envelopes or postcards. Though they passed through a censor - most of the early letters are stamped with the word "zenseirt" in black ink - and had to be written in German, a language the writers had to learn in order to send mail, the correspondences came through, usually in about a week. Hiding them was another story, and Garncarz did everything, from burying the letters to handing them off to friends, to keep from seeing them get lost or confiscated. Emotions brim from the cramped handwriting, often expressing the tragedies of the war, but there are also more prosaic sentiments ("I ordered skin cream for youâ€¦"). And there is love. Garncarz had her first real relationship in the camps with a man named Harry Haubenstock who, once deported, continued to send her love letters. One that is displayed in the exhibit seems to have been folded over again and again as if Garncarz read it many times. In it, Haubenstock included a photo of the two young lovers peeking out from the door of a barracks. After 1943 the letters from her sister and Haubenstock stopped coming. Garncarz was moved to the last labor camp that she would inhabit until the day she was liberated. The only correspondences from this period are the elaborate birthday and holiday cards the women in the camp prepared for each other. When she was finally freed, Garncarz went looking for Haubenstock in Prague only to find that he was alive but married to another woman. But not long after, she too would become engaged to an American soldier, Sidney Kirschner. One of the most endearing letters in the collection is from Garncarz to her future mother-in-law in a stilted Yiddish in which she tells her that she is "a plain Jewish girl from a kosher home - that's all." Sidney Kirschner took his bride back to the US, to an apartment in Queens, where she would began a new life and remain silent about the war and her letters for nearly 50 years. When Ann Kirschner started leafing through the box of frail paper her mother had just given her, she was stunned. "It was like an electric shock," said Kirschner, a literary scholar and media consultant "And at the same time it was like something I had been waiting for my whole life even though I wasn't actually waiting for it." Kirschner took it upon herself to decipher the story contained in the letters, her mother's story, which, she said, had been locked in a "black box" until that moment. She gathered translators, made databases, and finally also sat for hours with Garncarz to listen to her recount the history. In the process, Kirschner also began to understand why her mother had been silent all these years. "She had the desire to put it in a box in the belief that it would somehow interfere with her ability to come to life again in the new world that she was building for herself and her family," Kirschner said. "And she had this fear that her experiences, her past, could somehow harm her childrenâ€¦The letters were her way of surviving during the war but after the war she felt she had to put them away in order to protect us and herself." As her sister, Raizel, wrote to her in one of the last letters in the collection, in 1945, after liberation, when she discovered her sister had survived, "I did not doubt that you were alive, but I could not figure out how you - the one of us who knew best how to survive - remained silent... Once more, we live for your letters."