Oskar Groening, former SS Auschwitz guard, goes on trial in Germany

Hedy Bohm had just turned 16 when the Nazis packed her and her parents onto a cattle car in May 1944 and sent them from Hungary to the Auschwitz death camp in occupied Poland.

After three days and nights in darkness, crammed into the standing-room-only car with babies wailing, the doors were flung open. "An inferno," is how she remembers the scene she saw.

"The soldiers yelling at us, guns and rifles pointed at us," she recalled. "Big dogs barking at us held back on their leashes by the soldiers."

One of the black-uniformed men on the ramp was likely SS guard Oskar Groening. Now 93, he wenton trial Tuesday in a state court in the northern city of Lueneburg on 300,000 counts of accessory to murder. Two of those deaths were Bohm's parents, who are believed to have been killed in the gas chambers immediately upon arrival in Auschwitz.

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Groening's trial is the first to test a line of German legal reasoning opened by the 2011 trial of former Ohio autoworker John Demjanjuk on allegations he was a Sobibor death camp guard, which has unleashed an 11th-hour wave of new investigations of Nazi war crimes suspects.

Prosecutors argue that anyone who was a death camp guard can be charged as an accessory to murders committed there, even without evidence of involvement in a specific death.

"He helped the Nazi regime benefit economically," the indictment said, "and supported the systematic killings."

Bohm is today 86 and lives in Toronto, where she moved after the war. She will testify as a witness about her Auschwitz experience, although she doesn't remember Groening. She is one of some 60 Holocaust survivors or their relatives from the U.S., Canada, Israel and elsewhere who have joined the prosecution as co-plaintiffs, as is allowed under German law.

Judy Kalmantold CBC's Carol Off that as the child of Holocaust survivors,"the deaths in my parents'familieshas been,really,a defining feature in my life."

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Kalman, one of the Canadians who is slated to testify, saidher father had a daughter who died in Auschwitz at six years old.

"She is the official person who I am representing here, as a half-sibling," Kalman said in an interview on As It Happens. "I'm named after her. I never knew her, but she has always been a part of me, there's always been a sense of her as my very eldest sister."

Groening admits he served, but denies crimes

Groening has openly acknowledged serving as an SS non-commissioned officer at Auschwitz, though hedenies committing any crimes. His memories of the cattle cars packed with Jews arriving at the death camp are just asvivid as Bohm's.

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"A child who was lying there was simply pulled by the legs and chucked into a truck to be driven away," he told the BBC in an interview 10 years ago. "And when it screamed like a sick chicken, they then bashed it against the edge of the truck so it would shut up."

His attorney, Hans Holtermann, has prevented Groening from giving any new interviews, but said his client will make a statement as the trial opens. Earlier, Groening said he felt an obligation to talk about his past to confront those who deny the Holocaust.

"I want to tell those deniers that I have seen the crematoria, I have seen the burning pits, and I want to assure you that these atrocities happened," he said. "I was there."