Demolition crews did more than tear down an old, abandoned building in Bridgewater today. They destroyed the old Dunlap Mansion, a national historic landmark that was once a safe house for slaves escaping to freedom on the Underground Railroad. The Borough of Bridgewater had a court order to demolish the mansion after giving the owner a year to sell the place or fix it up. The building had a rich history.  A tunnel remains where slaves entered the building.