On the night of 13th to 14th February, 1945, the allied air forces bombed the historic German city of Dresden.
"It was an art treasure. It was a wedding cake. It was a beautiful thing," said American novelist Kurt Vonnegut.
Mr. Vonnegut witnessed one of the heaviest air raids of the Second World War. He had been taken prisoner of war by the Germans in 1944, during the Battle of the Bulge - Hitler's last major offensive against the allied forces.
"We were working in a plant that made syrup laced with vitamins for pregnant women," Mr. Vonnegut said. Under the Geneva Convention, we couldn't do any work associated with armaments."
He says the prisoners could hear the bombs falling on nearby German cities, but the guards told them Dresden would not be targeted because only industrial and military centers were bombed.
In fact, the city of six-hundred-thousand residents and as many refugees had not even built adequate air-raid shelters. Mr. Vonnegut says he and about a hundred other American prisoners of war were luckier than most.
"It turned out we had a swell air-raid shelter because we were quartered in a slaughterhouse. And there was this wonderful, very deep cellar under there, where they hung meat, where it was cool, and so that's why we survived. That's why we weren't killed and everybody in our immediate neighborhood was dead."
Kurt Vonnegut's 1969 novel "Slaughterhouse Five" is based on his Dresden experience. He says it took him more than twenty years to learn the extent of the Dresden tragedy. About 60-thousand Dresden residents and perhaps twice as many refugees perished in the bomb fire, which reduced the city, known as Florence on the Elbe, to rubble.
During World War Two, the allies dropped altogether about one-and-a half million tons of bombs on Germany, killing more than 6,000 civilians, including about 80,000 children and turning hundreds of cities to rubble.
"World War Two was the last mass war. It was a war of masses, a war in which mass numbers, mass vehicles, mass civilian participation in the factories was vital."
Dennis Showalter is professor of history at Colorado College.
"I think World War Two was unique because it developed a strategy of attritional-conventional bombing that was designed to destroy or cripple the industry supporting a high-tech modern war and by extension the civilian morale - the civilian effectiveness - that in an environment of total war was considered as important as the fighting men.
The early failures of the British Royal Air Force led to the development of a tactic called area bombing. Instead of trying to hit a strategic target and risk losing a bomber to the German air defense, the planes would fly at a higher altitude and drop a heavy load of bombs to destroy a whole area around targets such as railway stations, factories, mines and others. The British also developed incendiary bombs, which continued destruction long after the planes had left.
James Corum, professor of comparative military studies at the U-S Air Force School of Air and Space, says German air raids on cities such as London, Coventry, Warsaw, Rotterdam and Belgrade were small in comparison.
"Dispassionate research, and we are talking about what the British are saying about the bombing of Coventry today, is that - looking back - it was clearly a military target, one, and two, the only mistake the Germans made was not coming back and bombing it again a few more times."
However, professor Corum points out the failure of the German Luftwaffe to level the cities it bombed was due to inferior technology -- not a lack of will. But for decades after the war, Germans did not dwell on their suffering or their guilt. No major literary works focused on intimate tragedies resulting from the massacre of people in their homes.
Jack James, director of the American Institute for the Contemporary German Studies, says the most obvious reason for this silence has been the enormous pain Nazi Germany caused other people. So the post-war Germans focused on reconstruction and establishing their country as a western democracy.
"But certainly, trying to re-instate the sense of morals and values. That required an enormous distancing from what the Nazis had done," Mr. James said. "So I think that there was just simply no real national interest in digging this up except for the pockets of activity and the groups that did. But for the most part, for these five decades or four decades, the Germans were happy to say we don't want to talk about it."