A tugboat working on the Memorial Bridge construction sank yesterday shortly before noon in the Piscataqua River. The 58 foot boat known as the Benjamin Bailey was moored up to a barge, when the strong current started bringing the boat under. Two people who were onboard the tug were able to safely get onto the barge before the boat tipped on its side and sank, and is currently sitting at the bottom of the river. Attempts to salvage the vessel yesterday were unsuccessful because of the tide, but the boat’s owner, Riverside and Pickering Marine in Eliot, ME, will continue efforts to raise it today. The New Hampshire Department of Environmental Services said there was no indication that the tug is leaking any fuel or oil. The US Coast Guard is continuing their investigation into the incident.