The historic superstructure Mill 19 reinhabits is the last remnant of the former Jones & Laughlin Steel Company, which once perched on the banks of the Monongahela River four miles east of downtown Pittsburgh. The Thirteen Colonies acquired the area in 1768 from the Iroquois in the Treaty of Stanwix, the first railroad came through in 1861, and the first steel plant was built in 1883. For over a century, the J&L Company steel mill supplied materials to an expanding nation, extending America’s claim across indigenous lands and its influence globally. RIDC, Mill 19’s developer, preserved the steel rolling mill’s quarter-mile-long shell for adaptive reuse while undertaking 13 years of environmental remediation. In 2019, Hazelwood Green opened to the public for the first time in nearly a century with the dedication of its first public streets and Mill 19’s first development phase, which houses CMU’s Advanced Robotics for Manufacturing Institute. Completed in 2020, Mill 19’s second development phase connects to an adjacent public park. Mill 19’s third phase of development is slated for completion in 2023.

Mill 19’s interiors are all business: the internal building layouts promote flexibility, clear space, and daylight to meet the needs of the high-tech tenants. Building A integrates a double-height lab space with a new girder crane for CMU’s Advanced Robotics for Manufacturing Institute. Building B uses a ground-floor façade of overhead garage doors to support the driverless car innovator Motional AD. Building C is designed to be subdivided into multiple tenant areas on each floor to incubate smaller start-ups within the high-tech sector.