Starting Wednesday night at sunset, Israel marked Holocaust Remembrance Day. Commemorations continued in schools around the country Thursday, including in kindergarten classes.

This year, Israel is fully implementing a Holocaust curriculum for kindergartners.

"We need to teach the kindergarten teachers what to do on Yom Hashoah, because they have to make sense of the day," says Yael Richler-Friedman, using the Hebrew name for the remembrance day.

She is a teacher trainer at Yad Vashem, Israel's World Holocaust Remembrance Center, and she helped write the kindergarten materials. They are part of a new comprehensive Holocaust studies program for Israeli students of all ages that was unveiled two years ago.

The program took time to take root, Richler-Friedman says, in part because of bureaucracy, but also because of the difficult subject.

"A lot of times, I see teachers and they say, 'Don't speak with me about it,' " she says. The teachers tell her, "It will take me to dark places. I don't want it."

But they can't avoid it in Israel. Even in kindergarten.

Every year on Holocaust Remembrance Day, an air raid siren wails for two full minutes. Around the country, people stop whatever they're doing — driving, working, talking — to stand still and remember. Even on highways, cars come to a halt.

The evening before, regular TV shows are canceled and special Holocaust-themed programming airs. Shops close early.

Nava Ron, a veteran kindergarten teacher, says 4- and 5-year-olds know this day is different.

"You can't ignore it. It exists. There's the siren," she said, sitting in a low blue plastic chair in Jerusalem's "Rainbow" kindergarten. "Our job is to keep them calm and not give them too much information."

This morning, she brought together her six oldest kindergarten students for a special conversation.

"Good morning, children," she said.

"Good morning," they chorused.

Then she began: "This is a very special day."

In 10 minutes, Ron touched on all the main points that Israel's education ministry wants communicated to kindergartners. First, she tells them the Holocaust is something that happened a long time ago, in a country far away from here.

Then she asks the children what they know about it. One child says Israeli soldiers protect them now. Another pipes up and says at that time, the whole world was at war.

Ron agrees. She directs the conversation toward democracy, tolerance and other ways to solve conflicts.

Richler-Friedman, the Holocaust educator, says Israel standardized the kindergarten material, in part, because some teachers were saying too much. "Telling them about the gas chambers. The horrible person who wanted to kill all Jews and if he would live today, also he would want to kill all the Jews. Something that is very frightening. Even sometimes using pictures. Horrible pictures," Richler-Friedman says.

Last year, some Israeli parents were outraged when their children came home on Holocaust Remembrance Day wearing yellow stars, the symbol Nazis forced Jews to wear to label and discriminate against them.

Another problem Richler-Friedman regularly sees is kindergarten teachers who simply avoid discussing the Holocaust, despite all the references children are regularly exposed to in Israel. Some, she says, pretend the siren is an emergency drill or an ambulance.

"Saying the siren is an ambulance or something like that — it's not an educational act," Richler-Friedman said. "It's lying."

But she is sympathetic, saying kindergarten teachers face the same struggle many people do when they really consider the Holocaust.

It can't be forgotten. But it contradicts the humanity people want to pass on to their children.

Don Futterman, director of the Israel Center for Educational Innovation, still remembers terrible Holocaust photos he says he saw when he was way too young. When the siren began Thursday, he stopped his car, got out and saw other things.

"I could see a building-sized billboard advertising new hoodie sweatshirts," he says. "I could see the Israeli flag in my car. I could see all these other things of life that [are] going on since then. And I thought, that also makes sense. That was right. Because life does continue."

Back in Jerusalem's "Rainbow" kindergarten, Nava Ron gathered all the children just before the siren started Thursday, and invited them to make the siren sound. They all knew how. When the real one began, some of them came to her for a hug.

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