Crews are planning to retrieve a tugboat that sank in the Piscataqua River, forcing two people to quickly escape. The two people on board were able to get onto a nearby barge Wednesday and are safe. The tugboat, called the Benjamin Bailey, is owned by Riverside Marine in Eliot, Maine. The business is a subcontractor to Archer Western, the firm working on the construction of the new Memorial Bridge connecting Portsmouth, N.H., to Kittery, Maine. It’s not clear why the tugboat went down. The U.S. Coast Guard is in charge of retrieving the boat. It planned to attempt to raise it Thursday.