Chicago River: Chopped Ice, Anyone?

Now here is something that I don’t see very often!  During the winter months the Chicago River (which meanders its way through the downtown area) flows without too much interruption.  However, as I strolled by last week I couldn’t help but see the ‘puzzle-like’ pieces of ice banging into each other on the river’s surface.

Now, can someone please come along and put the pieces back together again?

Most puzzling indeed………………