“Who do you blame – the bystanders or the perpetrators?” a small boy with glasses at the back of the room asked.

As a granddaughter of Holocaust survivors, I had just finished presenting my grandparents’ stories to a classroom of 7th graders in Harlem.

I was used to getting questions about how my grandfather was able to rebuild his life in America after losing his entire family – except one brother – to the Nazi gas chambers. Students often also wanted to know more about my grandmother’s experience hiding in the mountains of Slovakia as a young child.

But this question was different. I paused for a moment, unsure of how to respond.

And then I remembered a story my grandfather had shared with me several years ago when my family visited Auschwitz.

My grandfather and I were walking along the train tracks at the entrance to the death camp, the same tracks that had brought him there just 65 years earlier, when he suddenly stopped and pointed to a flower.

“Sara, did you know that I used to plant flowers here?” he asked. I looked at him confused.

“A few days after I arrived at Auschwitz,” he continued, “a guard at the camp asked if anyone knew how to plant flowers. I raised my hand.”

As a result of volunteering to plant flowers at Auschwitz, he received an extra slice of bread per day. This went on for several weeks until one day a new transport of Jews arrived and some of the prisoners accidentally stumbled over the flowers that he had just planted.

“The guard saw this, and immediately demanded that I beat up the Jewish prisoners who had ruined my plantings,” my grandfather said, “But I refused.”

My grandfather could have been killed.  Instead, he was lucky – he lost the gardening job and the extra piece of bread.

I asked him why he refused the guard’s orders. “I owed it to myself and my fellow man to act like a human being,” he said. And that was it.

People often ask, “Where was God in Auschwitz?” But as Rabbi Abraham Joshua Heschel once wrote, “The question about Auschwitz is not where was God, but where was man.”

To be sure, there were righteous individuals. During the Holocaust thousands of non-Jews refused to be bystanders in the face of the evil that surrounded them. Many, including the family that hid my grandmother, risked their own lives and the lives of their families to rescue and save Jews.

But there were many more who did nothing, both in Europe and in the broader international community.

Many bystanders to the Holocaust claim that they were not aware of the horrible atrocities being committed by the Nazis. But researchers at the United States Holocaust Memorial Museum recently documented a staggering 42,500 Nazi ghettos and camps throughout Europe, spanning German-controlled areas from France to Russia and Germany itself.

And what of the British White Paper in May 1939, approved by the British Parliament, severely limiting Jewish entry into Palestine despite knowledge of the Nazi’s intent to exterminate European Jewry? Or what of the Roosevelt Administration’s failure to bomb the Auschwitz Birkenau death complex in the summer of 1944?

Two weeks ago during his trip to Israel, President Barack Obama listened as Rabbi Meir Lau, a survivor of Buchenwald and the former Chief Rabbi of Israel, spoke of reuniting a few years ago with one of the American soldiers who had liberated him. The retired brigadier general, Leo Hymas, had said, “Rabbi, I was one of the liberators of Buchenwald, I served with General Patton…I am asking you for forgiveness, for being late. We came too late.”

This year, Yom Hashoah coincides with the Commemoration of the 19th anniversary of the 1994 Genocide in Rwanda. In A Problem From Hell: America and the Age of Genocide, Samantha Power concludes, “the U.S. government knew enough about the genocide early on to save lives, but passed up countless opportunities to intervene.” The genocide in Rwanda could have been prevented. Instead close to a million Rwandans were murdered.

“Let there be no mistake,” Irwin Cotler, a Member of the Canadian Parliament wrote earlier this week, “Indifference and inaction always mean coming down on the side of the victimizer, never the victim.”

Today, on the 68th anniversary of the Shoah, we must come together and vow to speak up against racism, vow to speak up against hate, vow to speak up against anti-Semitism, vow to speak up against genocide.

As the generation of Holocaust survivors becomes fewer and fewer in numbers, it is becoming even more important that stories like my grandfather’s story – stories of survival and bravery – be shared and repeated over and over again. The stakes of remaining silent are too high.

I answered that 7th grader’s question in that Harlem classroom as best I could. I shared one of my grandfather’s stories, the one about planting flowers in Auschwitz. I hope the students in that classroom, the new generation, and also my generation, listen to the stories and tell the stories. I hope our generations “will not be late.”