Seventy-five years ago this week, in the final months of World War II, the British Royal Air Force and U.S. Army Air Force launched two days of massive bombing raids on the city of Dresden in eastern Germany.

The result was carnage. A beautiful city was transformed into a death trap. Homes, factories, and great centers of culture collapsed into a sea of furious, uncontrolled fires. Twenty-five thousand people are believed to have been killed, the vast majority of them civilians. In the context of this destruction, and because the raids occurred when Nazi Germany’s collapse was all but certain, they were immediately controversial. Some suggest the bombing raids were actually war crimes.