Bridj, the Boston-based on-demand bus service, is closing up shop after failing to close a “major deal” with an unnamed car company, the founder explained in a Medium post yesterday.

“After three years and millions of passenger miles as the largest operation of our kind in the country, Bridj is winding down,” wrote Matt George, the CEO of the pop-up transit service. He went on to describe the details of how his company collapsed:

We made the strategic choice to pursue a deal with a major car company who promised a close date for a sizable transaction in lieu of a traditional venture capital funding round. The close date timeline extended from weeks to months, as they sought to gain the appropriate internal approvals that we (and they) thought were already in place. Throughout, we remained convinced of the close strategic fit and both sides had every expectation that the transaction would close. Despite assurances, and all parties acting in the best of faith, that didn’t happen.

Over a year ago, the future of Bridj was looking bright. The startup had just announced plans to team up with Ford to launch an on-demand bus service in Kansas City. Essentially, Bridj worked like Uber, but for buses: tap an app, reserve a seat on a 14-passenger shuttle bus operating at fixed times, then get taken to your destination. The company also operated its pop-up bus service in Boston, Austin, and Washington, DC.

It’s unclear whether the “major” car company deal that failed to go through was with Ford. Spokespersons for both companies did not immediately respond to a request for comment.

It was only a few months ago that Ford was touting its partnership with Bridj at the Detroit Auto Show. But even then, it was clear that the auto giant was taking a different approach to Bridj than it was with other startups. Unlike its “partnership” with Bridj in Kansas City, Ford acquired rival startup Chariot in San Francisco. It was a sign that all on-demand bus services were not equal in the eyes of Ford.

(It’s worth noting: in addition to George’s farewell post, Bridj’s website currently features the entire lyrics to Kenny Rogers’ “The Gambler.”)