New Jersey’s Democratic U.S. senators have introduced legislation to block warehouses from being converted into immigration detention centers, following the federal government’s $129.3 million purchase of a 470,000-square-foot warehouse in Roxbury. The property, located on Route 46, is expected to be converted into an ICE detention facility capable of holding up to 1,500 people. The building had been vacant for two years and was sold by Dalfen Industrial and its investment partner, Goldman Sachs