People began taking seats on the Greene County courthouse wall about 8 p.m. Monday to watch a demolition company, Noralco Corp. of Pittsburgh, begin taking down the former People’s National Bank Building, also known as the old county office building, on High Street. Many of the observers were still there at about 11:50 p.m., when an excavator, with a boom and arm long enough to reach the top of building, began its work. The company is expected to continue its activities at night for the next few days. The demolition is scheduled to take three to four weeks to complete. The six-story building, constructed by the bank in 1906, was purchased in March by Waynesburg University, which determined the building would be too costly to renovate. The use of the property has not yet been determined. According to the university, that will be considered when Waynesburg Borough, the county and university jointly meet to begin revising the borough’s comprehensive plan.