Should novelists write about the Holocaust?

There are certain topics that it's probably impossible and maybe even presumptuous to write about, and at the top of the list would be the experience of transportation to one of the German death camps in WWII. Credit Vasily Grossman for giving this a try - and he earned the right to do so in that, as a Soviet journalist, he was the first to write about the Treblinka death camp at the close of the war; also, we have to recognize that the story was not as widely known in the 1950s when he was writing Life and Fate as it is today. Also, though there are survivor memoirs, all of them powerful, b definition there are no memoirs from those shuttled immediately to their deaths - leaving the field open for novelists. All that said, reading through the section on the transportation to the gas chambers in Life and Fate, I keep thinking that it's not his writing or even his observations that make this section powerful - it's the facts behind the story, the facts that we know to be true - as if this part of the novel could not possibly be imagined, if it weren't true we'd dismiss it as "over the top." Why does he write this section? First, his strategy as a novelist is to tell the story of an era (1940s Soviet) by including everything, an overwhelming crowded tapestry of people and events, a vast, compendious Breughel rather than a dramatic, focused Rembrandt canvas. Second, he was bravely recognizing that many Russians were willing accomplices to the Nazi invaders, particularly in regard to anti-Semitism - this above all probably prevented publication of Life and Fate during his lifetime. It's worth reading this section, and it would have been a form of moral censorship to cut this section from this vast novel, but you come away from it feeling that it's an area that novelists should probably stake out as off limits - there's nothing that fiction can add to the accounts of those who knew, those who suffered, those who died.