Irene Kolb, 94 and living in Florida, had finally resolved to tell the whole story of how she survived being a prisoner at Auschwitz.

In a telephone conversation with her granddaughter in January, Kolb described being held in a cell just three rows from the concentration camp’s crematorium, close enough to smell and hear its horrors. She also recounted the 2 a.m. roll calls, where prisoners were forced to stand up straight or face execution. Kolb was in danger of falling over from starvation, but she was preserved by her fellow cellmates, her sister and a Polish Catholic girl, who held her up when she was weak.

Dr. Channa Kolb-Sobieraj, Kolb’s granddaughter, pulled over while driving to take the call, knowing that she had never heard all the details and that Kolb had fainted years before when trying to tell the story to an interviewer from a cable television program.

The week after Irene Kolb called her granddaughter, she died.

“Her secret to her longevity was never holding a grudge,” Kolb-Sobieraj, 32, said Sunday in an interview after she lit a candle in memory of both of her grandmothers during a Holocaust commemoration.

Kolb’s parents and three of her siblings died in the Holocaust, but Kolb was not bitter, and she worked for a German family as an au pair after she was liberated, said her granddaughter, who lives in Williamsville.

All four of Kolb-Sobieraj’s grandparents are Holocaust survivors, but the most comprehensive retelling of the events in the camps came from her grandmother Irene, she said.

It is stories such as Kolb’s that are vitally important to preserve, speakers said Sunday to more than 600 Jews who gathered at Temple Beth Tzedek in Amherst for the annual observance of Yom HaShoah.

“We have a duty to do what we can to prevent future genocides,” said Gabriel J. Ferber, chairman of the 2013 Yom Ha- Shoah Committee.

Yom HaShoah is held every year after Passover. This year’s commemoration lasted about two hours and included a reading of a list of young Holocaust victims, musical selections, a reading of Psalm 23 and an address from Michael Berenbaum, a Holocaust scholar.

Six candles were lit in honor of the 6 million Jews who died in the Holocaust, and stories were told of survivors, such as Irene Kolb.

While it was a solemn, at times emotional observance, Ferber said it was not meant to be depressing, reminding those gathered that Hitler is still dead and that the Jewish people still live.

“It’s just another way of never forgetting,” said Daniel Serure, 74, of Williamsville. “You stop and wonder why – how man could be so mean.”

Berenbaum, who was involved in the creation of the United States Holocaust Memorial Museum, told those assembled that they are privileged, because they live in a time when some Holocaust survivors are still in their midst, but they have enough distance from Holocaust to grasp how important it is.

“If you look back too soon, you’re paralyzed by grief; you can’t go forward,” he said.

Telling the stories of survivors restores humanity to the victims, whose skin was marked with a tattooed number, he said, adding that it is everyone else’s responsibility to listen.

“The worst thing to do is say, ‘No, no, no, don’t go there, you’re frightening me,’ ” he said.

Knowledge of what happened should be used to deepen the ethical consciousness of humanity, he said.

“That’s not an easy task, but we don’t live in an easy world,” he said.