Halbreich was among the first Jews to be sent to the camps in 1939. Five-and-a-half years later, he was one of the few to emerge alive.
After moving to Los Angeles in 1960, he became one of the Holocaust's most vocal witnesses, giving talks in elementary schools, high schools, colleges, churches and synagogues. By the time he stopped, about three years ago, he had given 2,500 free lectures around the world on the abominations he lived through during Hitler's reign.
"Very few people were imprisoned as long and in as many prisons as he was," said John K. Roth, a Holocaust scholar and professor emeritus at Claremont McKenna College, who frequently invited Halbreich to speak to his classes. But he said what Halbreich accomplished after leaving the camps was also extraordinary.
"He would speak with great truthfulness about the hard things he had seen and endured. But there was always a note of determination to go forward," Roth said, "to help people remember that the world can be a brutal and nasty place, but that it doesn't have to be that way."
In 1996, Halbreich told a group of Riverside high school students that it was "not a pleasure to go . . . from place to place to talk about the horrible past we had to endure. But I feel it is my obligation to tell people what was going on and to warn them. This," he said of the Nazi's campaign of extermination, "should never happen again to anyone."
Halbreich was born Nov. 13, 1909, in the town of Dziedzice in what is now southern Poland. He had a degree from the University of Krakow and worked as a pharmacist until the war began.
In 1939, after the German army occupied Poland, he tried to escape to what was then Yugoslavia, but he was caught and deported to the Sachsenhausen camp north of Berlin, where he and 400 other prisoners were jammed into a barracks built for 100.
In 1941, he was transferred to the Gross-Rosen camp in what is now Rogoznica, Poland. A year later, he was sent to Auschwitz, where, because of his pharmacy training, he was assigned to work in the camp hospital.
Secretly he led resistance efforts, he told The Times in a 2004 interview. He sheltered younger prisoners, gave them food and medicine and helped many escape the brutality of their captors.
He was at Nordhausen-Dora, a forced-labor camp in central Germany, for a year before it was liberated by Allied forces in April 1945.
After the war, Halbreich, who spoke several languages, worked with the United States government's War Crimes Branch as an interpreter and investigator.
He testified at the trials of Nazi war criminals and gave testimony that was used in the prosecution of Adolf Eichmann, the German high official who was hanged in Israel for his role in the Holocaust.
In 1946 Halbreich immigrated to the U.S., and he spent the next 13 years in Cleveland, where he and his wife, Ruth, started a family. In addition to his wife, he is survived by a son, Jeremy, of Dallas; a daughter, Emily Tigerman, of Sherman Oaks; and two grandchildren.
He left Cleveland in 1959, in part to escape the past that came up every time a well-meaning relative asked about his wartime imprisonment. He moved to Beverly Hills and ran a custom picture framing business in Santa Monica. "Questions, questions, so many questions. I didn't want to talk much about what I had been through," he told the Cleveland Plain Dealer in 2000.
But in 1960, after a visit to Israel, his rabbi asked him to give a talk about the Holocaust. Halbreich agreed to tell his story -- and he told it again and again over the next 45 years.
He spoke of losing his parents and both his brothers.
He spoke of seeing Jews treated worse than cattle on trains bound for gas chambers, of a Nazi commander who sent Jews to hard labor or death with the casual flick of a thumb, of fellow prisoners shot dead for no reason other than that they turned their heads at the wrong moment.
He recalled how one day after liberation, while serving as an interpreter for Gen. Dwight Eisenhower, the Allied commander noticed the "68233" that the Nazis had imprinted on his skin and asked, "Did it hurt you very much when they tattooed this number on your arm?"