Flying cars are being touted as the next big thing, but one company hoping to cash in on the urban air mobility boom has been permanently grounded.

Kittyhawk, which takes its name from Kitty Hawk, NC, the location of the Wright brothers’ pioneering early flights, set up in the eVOTL (electric vertical takeoff and landing) business in 2010 and was backed by Google co-founder Larry Page.

It hoped to develop short-distance pilot-less air taxis that could be operated easily and cheaply with the ability to take off and land from urban locations that were difficult for conventional aircraft to access. Bloomberg reports that the company wanted to charge less than $1 per mile for rides. But the company announced yesterday that it was closing down.

“We have made the decision to wind down Kittyhawk,” the firm tweeted. “We’re still working on the details of what’s next.”

Related: Hyundai Expects Flying Urban Taxis To Take Off Before 2030

Kittyhawk partnered with Boeing to create Wisk Aero in 2019, the legacy aviation company investing $450 million in the operation as it attempted to work out how eVTOLs and conventional aircraft could operate together.

But it looks like Kittyhawk’s demise won’t affect Wisk’s future. “Kittyhawk’s decision to cease operations does not change Boeing’s commitment to Wisk,” a Boeing spokeswoman told Bloomberg. “We are proud to be a founding member of Wisk Aero and are excited to see the work they are doing to drive innovation and sustainability through the future of electric air travel.”

Many automakers have been keen investors in the burgeoning eVTOL industry as they look to shift from being companies that build and sell cars to ones that provide mobility solutions. Honda, Hyundai, Mercedes, Stellantis, Toyota and others are all involved in the industry, and this summer Volkswagen Group China unveiled its first prototype aircraft. But the industry still needs to satisfy regulatory bodies around the world that eVTOLs are safe before the flying taxi business is ready for launch.