CCA Civil was responsible for Site L, a significant component of the plan. The Site L project consisted of constructing a two-story ventilation building structure that included concrete work, exterior cladding, roofing, interior partitions and stairs. The underground construction included mining and lining two shafts approximately 120 feet below street level and two entrances that connected the two bored tunnels on the No. 7 Line to the ventilation shafts. A cross passage also was constructed to connect the two new tunnels between the two entrances and Times Square Station.