The Army Corps of Engineers were summoned to the Sagamore Bridge in Bourne Monday afternoon after large potholes appeared on the eastbound lanes.Concrete pieces came loose from the roadway and were knocked out of place by traffic going over the bridge. Bourne Police say both eastbound lanes were closed on twice while there was a closure of one lane in each direction for a brief period.Police say the lanes closed down around noon and were back open an hour later.