In a brief note to staff on Thursday, the company formerly known as Twitter announced that its longtime office and global headquarters in San Francisco will close in two weeks, on Sept. 13, according to one person familiar with the announcement.

That date happens to fall on a Friday. Friday the 13th is a superstitious day of bad luck for some people. It is also a well-known horror film franchise. Reporters from the New York Times also reported on social media that X had told staff the office will close Sept. 13. A representative of X did not respond to an email seeking comment.

The portentous closing date adds a darkly ironic twist to the company’s San Francisco story. Twitter took over the building—an expansive, 1 million-square-foot Art Deco structure that once served as a furniture showroom—to much fanfare in 2012, garnering a controversial tax break from the city in the process. The presence of Twitter, it was hoped, would revive the gritty mid-Market neighborhood. Soon after Musk became Twitter’s owner two years ago, he fired thousands of employees, auctioned off much of the furniture, and abruptly ripped down the large Twitter sign on the exterior of the building. Several floors of the building have effectively been closed ever since.

Prior to Thursday’s note about the closing date, X workers were left in the dark about the San Francisco office closure, having been told nothing from CEO Linda Yaccarino since an email at the start of August saying the closure would happen. Employees in San Francisco will be moved to offices in San Jose or Palo Alto. X’s headquarters, meanwhile, is expected to move to Texas, where other Musk companies such as Tesla, SpaceX, and the Boring Company are also based.

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