rented out. his only hobby seemed to be home repair. >> translator: herr fritzl was always very hard working. we often heard the noise of a cement mixer. i think herr fritzl did most of the building work himself. we thought he was adding on an extra room to rent out or something like that. >> according to the police, years before imprisoning his daughter fritzl carefully planned and built his maximum security prison. >> one of the strangest things about the fritzl case is the amount of preplanning, not just premeditation, i assume, about what he wanted to do to his daughter, but the amount of planning to enable him to build this bunker, fortify it, make sure that nobody in very close quarters could hear anything in it. >> translator: today we know with certainty that part of the old cellar in the old house was kept back as a reserve, so to speak, and that this news house