By the end of December 1931, the steel frame had been erected to the fourth floor. Derricks were positioned so that one or two tiers of framing could be erected before they needed to be moved up. Columns in most steel framed buildings are two stories tall, each two story unit a "tier." In this photo, the buildings on the corner of Wall Street and Broadway, the First National Bank and 6 Wall Street, have been completely demolished. The beams at the perimeter of the building--at the west lot line--are visible; beams at the lot line have been set outside the column line to allow construction of a fire-rated masonry enclosure at the party wall.