As San Francisco's office market tanked, one developer kept building its new tower FacebookTwitterEmail 1of7 Construction takes place at 415 Natoma St. in SoMa this month. The $158 million, 640,000- square-foot building is part of the larger 5M development, featuring residential, office, retail, recreational and other space.Marlena Sloss / Special to The ChronicleShow MoreShow Less 2of7 3of7 Construction takes place on the steel beams at the top of the 415 Natoma St. office building.Marlena Sloss / Special to The ChronicleShow MoreShow Less 4of7 The San Francisco Chronicle building’s restoration and 415 Natoma St.s construction are part of the 5M development project.Marlena Sloss / Special to The ChronicleShow MoreShow Less