The stunning collapse of WeWork entered a new stage Monday after the company officially filed for Chapter 11 bankruptcy protection. Once worth north of $47 billion, the short-term office rental venture was at one point the United States’ most valuable startup—until fallout from a slipshod initial public offering and pandemic-driven market forces decimated its revenue base and doomed the company for good. The declaration will only affect WeWork locations in the U.S. and Canada, WeWork said in a statement on the filing.