How many art pieces were lost during world war 2?

It is estimated that around 13 to 16 million art pieces were lost, stolen, or destroyed during World War II. The conflict led to widespread looting and the deliberate destruction of cultural heritage across Europe. Many artworks were taken by the Nazis, and while some have been recovered, a significant number remain missing or unaccounted for today. The war had a profound and lasting impact on the art world, highlighting the vulnerability of cultural treasures during times of conflict.