This is another take on the underpinnings of the westbound side of the Washington Bridge spanning the Seekonk River between Providence and East Providence. 
Have another look....because it is now gone. Apparently it was experimental construction in its day - and they didn't continue using this approach...for good reason.

We are looking from under the eastbound bridge which was built with different construction and is reportedly safe and sound. It sounds like it will be several years before we have a new westbound bridge.