Sentence:  The skylight, although it had been bricked up by someone's hysterical order, at that time in the past when a man had penetrated the attic-floor of the club to visit a girl, was not beyond being <WSD>unbricked</WSD> by the firemen. It was all a question of time. 
Meaning of the word marked with <WSD> tags:  To reopen something bricked up.