It was the freight car that took Jews to Treblinka that convinced me, as if I hadn't known before, that my daughter Sarah has a tender heart. She and her friend Carrie--two 13-year-olds--had walked through the car, perhaps not certain what it was, or perhaps too sure what it was. And I, on my second visit to the U.S. Holocaust Memorial Museum in Washington, was still paralyzed by this rolling coffin.

I stood there, staring at the wooden walls still etched with deep scratches from fingernails, when Sarah came over, put one arm gently through mine, and whispered, "Come on, Dad." Then she gently guided me toward the door in an exit from Freight Car No. 11688 far more graceful than allowed those who had been crammed into it for a one-way ride to hell.

I had been fearful about how Sarah, who is Jewish, and Carrie, the daughter of an Episcopal minister, would handle the museum. I was torn between protecting them from the horrors and wanting them to know the truth. And I couldn't help but think that had Sarah been in Europe during the Holocaust, she almost certainly would have been, like Anne Frank, among the 1.5 million children killed. And that Carrie, with her good heart, would surely have been among those gentiles who tried to save the doomed.

"They kept saying, 'It's a European problem,' It's just like Bosnia or Kosovo today."

Carrie knew little about the Holocaust; Sarah knew about the gas chambers and German scapegoating of Jews for their country's economic and social problems. Both approached the museum soberly and a bit reluctantly. Their hesitations were justified. Sarah grimaced as soon as we left the elevator on the museum's top floor: Facing her was a large photo mural of American soldiers staring at charred Jewish bodies in Mauthausen, a concentration camp they had just liberated.

Surprisingly, the girls' interest in the museum never flagged. They sat for 20 minutes before a small TV screen that documented Americans' insistence that the U.S. must, as FDR said in 1935, "remain unentangled and free." They learned about the debate over whether the U.S. Olympic team should participate in the 1936 games in Munich--and about the covert order by the head of the U.S. Olympic Committee forbidding two Jewish team members to participate.

They also learned that, in the late 1930s, although 94 percent of Americans disapproved of German actions against Jews, 77 percent opposed giving Jews refuge in the U.S. "They kept saying, 'It's a European problem,'" Carrie said. "It's just like Bosnia or Kosovo today."

Perhaps because the museum hits us at such a personal, deeply human level, whom we go there with helps determine what we get out of it. (When we go is a factor too. One of the more potent times to visit is on Holocaust Remembrance Day, which this year is on May 2--a day when Holocaust commemorations will be held in most states and at the U.S. Capitol and, of course, at the museum.)

My first visit was with Gigi McKendric, a Holocaust survivor in her late 50s. Many survivors are reticent about their experiences; McKendric is more so than most. For her, the most painful exhibit was a four-story "Tower of Faces": 1,000 photos taken between 1890 and 1941 of Jewish life in the Lithuanian town of Ejszyszki. In two days in September 1941, Nazis shot the town's entire Jewish population of 3,500 people. "Each face feels like a relative," she said.

Visiting with the kids was different but just as potent. Upon entering the museum, McKendric didn't need to take an ID card of "a real person who lived during the Holocaust"--she was one. But Sarah and Carrie took the cards they were issued: Sarah's had a photo of a very young Esther Morgensztern, pudgy and wide-eyed. Carrie's had a photo of Felicia Karo, who seemed to be in her mid-teens. Both were Polish Jews.

To follow what happened to the girls, Sarah and Carrie inserted the cards into computerized "printing stations" located on each floor. On the third floor, for example, we found out that Carrie's girl was sent to the cramped and diseased Lodz ghetto and that in 1940 Sarah's moved in with relatives.

I had originally dismissed the ID cards as a hokey, high-tech gimmick--a well-intentioned but Disney-like stab at personalizing the Holocaust that was incongruous with the somber tone of the rest of the museum. I was wrong. The cards actually help visitors relate to victims as individuals, not as another integer that finally totaled the sum of 6 million. One woman clasped her ID card to her breast with relief when she discovered that her person had survived; another muttered, "Those bastards," when her victim died from medical experiments.

The cards especially help sustain kids' interest in an exceedingly difficult museum. As Carrie said, "It made me think, 'Am I going to make it through this floor?' or 'Am I going to make it to the end?'"

Carrie's "real person" did survive the war: British troops liberated her from Auschwitz in April 1945, three days after her 19th birthday. Sarah's died in Treblinka in 1942 at age 15.

The museum restores our faith in humanity, for its horrors unleash as much sweetness among visitors as disgust within them.

Despite all the sadness and depravity and death, the museum allows visitors to leave with a measure of hope that the human spirit can't be fully extinguished. Such faith comes from the exhibits about resistance to the Nazis and about gentiles who helped Jews during the war. It's also kindled by tender moments in the museum itself, for its horrors unleash perhaps as much sweetness among visitors as disgust within them.

One such moment occurred in the middle of an actual barracks from Auschwitz, where visitors surrounded several TV monitors. Sarah and Carrie squirmed through to the front of the crowd. A few minutes later, they squirmed back out.

"Ugh," Sarah said. "Films of medical experiments."

I still stood there, waiting for the small crowd to disperse. Finally, Sarah said softly but persuasively, "Dad, you don't want to see that." She was right.

We walked on, Sarah lost in her healthy 13-year-old's curiosity about a world gone bad and I glad that she'd come with me, assured from her solicitousness that she has the compassion needed to help banish the sort of evils with which the Nazis tainted our collective souls.

If nothing else, instilling such resolve is the main purpose of the museum. If visitors walk away from it thinking that the 12 years they have just learned about are merely a history lesson--something that started abruptly in 1933 and ended conclusively in 1945--then the museum is a sham and the $169 million spent on it went down a very dark hole. Thankfully, Sarah and Carrie's reaction to it convinced me otherwise.