Historical Archive of the City of Cologne up at the site of the collapse (a large hole in the ground), where around 95% of all archival items could be held until August 2011, albeit scattered and in many cases badly damaged. Archive repositories all over Germany offered space to store the damaged and only roughly cleaned documents: wet materials were flash-frozen to prevent mold growth. "Itinerant archivists" worked in the receiving archives all over the country and began the task of re-identifying and re-cataloging. A newly installed centre for restoration and digitization on the outskirts of Cologne started working in 2011, with a total cost for restoring
Historical Archive of the City of Cologne so-called White Book ("Weißes Buch"), a book of copies of charters and privileges. By 1370 the archives were located in the "Haus zur Stessen". In medieval Cologne, valuable goods and important trade documents were frequently stored in vaulted warehouses specially built in backyards. This method of storage was used by both business owners and the municipal administration. Documents included grants of privileges, contracts, records of lawsuits, maps, seals and documents from the estates of important persons. As the city and its national and international trade thrived and prospered, the municipal administration began to plan further storage to house the growing