Elon Musk’s social media company, X, formerly known as Twitter, has reportedly announced the closure of its San Francisco headquarters on the eerie date of Friday, Sept. 13. What Happened: X employees were informed about the closure of the San Francisco office through a brief note on Thursday, reported Fortune. The San Francisco office, a one-million-square-foot Art Deco building, was leased by Twitter in 2012 with much celebration. The company’s presence was anticipated to revitalize the mid-market neighborhood. However, after taking over Twitter two years ago, Musk implemented significant ch…