Workers are building a causeway that will be used in the demolition of the Skinners Falls Bridge over the Delaware River.

While a traditional concrete box girder is the preferred choice—due to its cost-effectiveness and the availability of natural riverbed sand and stone—engineers are also considering a steel truss ...

The steel truss, single-lane ... of crashing stone punctuated the air. The mechanical forces worked methodically beneath the bridge, so far still in place on its two abutments and center pier.