MARQUETTE, Iowa (AP) – Inspectors following up on a report that a piece of a Mississippi River bridge fell off have let the bridge reopen in northeast Iowa.   Officials closed the bridge Sunday for about three hours. It connects Marquette, Iowa, with Prairie du Chien, Wis.  The Iowa State Patrol says a passer-by reported seeing something fall off the bridge.  Wisconsin bridge inspector Joe Langeberg says a piece of concrete had fallen off a haunch over the main river channel. Inspectors didn’t judge that a safety concern, so the bridge was reopened late Sunday afternoon.