Concrete core at 400 Lake Shore has risen above the Chicago Spire cofferdam
The famous Chicago Spire cofferdam continues its fade into oblivion, as the concrete core for the North Tower at 400 Lake Shore has cleared the top of the former hole in the ground. The core got some help, of course, in the form of a severe haircut for the concrete-and-steel cofferdam, which is being cut away piece by piece. The iron ring that appears in the photos below will be removed, leaving only the lowest portions buried deep in the ground.