Work to fill the basement with cement began Thursday and will continue for about two weeks, the BBC reported.
Fritzl, 78, was sentenced to life in prison in March 2009 after being convicted of murder for the death of one of the seven children he fathered with his daughter while she was imprisoned in his basement. He was also convicted on charges of rape, incest, and enslaving his daughter.
Austrian authorities decided in 2011 to demolish Fritzl's home in Amstetten.
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