Complex sentence: With the fall of the communist East Germany it was possible to do excavations in the former camps; in Sachsenhausen, the bodies of 12,500 victims were found, most were children, adolescents and elderly people.
Split into simpler sentences: With the fall of the communist East Germany it was possible to do excavations in the former camps. At Sachsenhausen, the bodies of 12,500 victims were found, most were children, adolescents and elderly people.