When I was younger I always wondered how so much of our cultural heritage is simply gone, and I learned of burned (and/or looted) libraries and other such disasters. “That,” I used to think, “surely can’t happen today.” Turns out it can: “The building housing Cologne’s municipal archive collapsed on Tuesday, bringing parts of some surrounding structures down with it. At least two people are missing. Some of the documents housed in the archive date back to the year 922.” (story) They’re building a subway nearby - go figure.
Update (4 March 2009): ” The archive’s collection of original documents included thousands from Cologne’s golden age. The founding charter of the University of Cologne, signed in 1388, was inside, along with the documents that established Cologne as a free imperial city under Emperor Friedrich III in 1475. Two of the four manuscripts in the hand of Albertus Magnus, considered the greatest German theologian of the Middle Ages, were kept in the archive’s rare books collection. […] The archives also contained the personal papers of almost 800 prominent German authors, politicians and composers, including Konrad Adenauer, the first post-war chancellor of Germany. The manuscripts and letters of Nobel Prize winner Heinrich Böll and Jacques Offenbach, a 19th century cellist and opera composer, were stored at the archive.” (story)
Oh, and get this (from that same article): “There may be no way to recover the lost collections. Large parts of the pre-1945 documents were put on microfilm and stored in a bunker in the Black Forest, but […] the microfilm is of poor quality. And the post-war collections — including records from the Cologne Art Association used to track the provenance of artworks — have no back-up at all.” (my emphasis)