POTSDAM - German officials plan next week to bury the ashes of thousands killed in the Nazis' Sachsenhausen concentration camp after they were discovered during building work at the site, the director of the camp memorial said yesterday. Archaeologists last year found a layer of ashes up to 1.5 meters thick underneath a concrete building constructed near the camp 's former crematorium by East Germany's communist authorities as a memorial , director Guenter Morsch said. Morsch said it was impossible to establish the number or identity of the victims whose cremated remains were found , but estimated that "there are...