New York Six decades later, the Holocaust remains a painful and emotionally draining topic - and a special challenge for middle school and high school teachers who have to instruct students about one of the most horrific episodes in human history.
Despite its importance, Holocaust scholarship is still just beginning to work its way into history lessons in much of the country, and teachers volunteering to tackle the subject often find themselves developing courses from scratch, without much formal training.
"My own education about the Holocaust was not close to what I am providing today in my classroom," said Kimberly Watkin, a history teacher in South Burlington, Vt., who offered her high school's first full-term course on the Holocaust this past school year.
To become better versed in her subject matter, Watkin joined about 30 other educators from 11 states, plus Croatia, Lithuania and Poland, at a five-day program on the Holocaust at Columbia University last week.
It was sponsored by the Jewish Foundation for the Righteous, which began in 2000 to bring schoolteachers from around the country to seminars with top historians as part of a campaign to improve teaching about the Holocaust.
"More often than not, you'll find that students are introduced to the Holocaust by an English teacher who wants them to read Anne Frank's diary," said the foundation's executive vice president, Stanlee J. Stahl.
"We did this because we discovered that teachers did not know the history," she said.
Established in 1986, the foundation's primary mission is to provide financial aid to non-Jews who risked arrest and possible execution to rescue Jews during World War II. It offers care to about 1,500 surviving rescuers around the globe.
But last week, it offered teachers lectures on the development of the Nazi regime, refugee policies, life under German occupation, the role of industry in the Holocaust, the efforts of rescuers and the machinery of the system that killed 6 million Jews.
As in the past, many of the participants came from schools in towns where there are few Jews, and where the Holocaust is generally taught over just a few days as part of a larger U.S. or world history course, or as part of a literature program.
In one seminar, Robert Jan van Pelt, a professor at the University of Waterloo and the author of several books on concentration camps, posed this question: Why did the death camps use gas for mass murder?
"Shooting," he noted, "is a perfectly fine way of killing people."
Guns, in fact, were the weapon of choice when mobile death squads began the first large-scale massacres of Jewish families in the Soviet Union in 1941. Why switch to stationary camps and gas chambers, which were less efficient?
The answer, van Pelt suggested, may have been that Nazi leaders were concerned that the relentless killing of women and children up close with a rifle would exact a psychological toll on German troops.
Gas "allowed those who took part in the operation to remain clean," he said. "The issue is not how someone could kill, but how they could continue to do it."