We screened it at Dwell on Design this year and I was part of another screening last month here for the San Francisco AIA's Architecture and the City festival, but now you can watch A Necessary Ruin online. Landscape architect and filmmaker Evan Mather's elegiac look at the Union Tank Car Dome is a great bit of architectural and regional history. The Baton Rouge, Louisiana, structure was a massive dome used to service railcars erected in the 50s. It's design employed all the tenets of Buckminster Fuller's geodesic domes, but the dome quickly fell into decay. Mather's film explores the history of this engineering marvel as he charts its inspiring construction and saddening demise. Watch it now!