Jackhammers in hand, three workers demolish the edge of the existing bridge over Coal Creek Parkway so that a new section of bridge can be added. The new section of bridge will carry a new northbound lane on I-405.A new retaining wall, still under construction, stretches along the ramp from westbound I-90 to southbound I-405. The wall will support a section of the new southbound I-405 bridge over I-90.Crews set rebar and forms for a retaining wall along the ramp from Coal Creek Parkway to northbound I-405.Crews pour concrete for a "cap" that will support the new southbound I-405 bridge.Concrete columns creep toward the sky, topped by "caps" that will support a new, three-lane southbound I-405 bridge over I-90. At right is the existing southbound bridge.