Charles Barr, founder and president of Webpass, the high-speed wireless internet provider acquired by Google Fiber last year to help fuel its expansion, abruptly left the company last week, according to two people close to Webpass.

The circumstances of his departure aren’t known. But it adds to uncertainty surrounding Google Fiber’s long-term future. In the past year, Google Fiber's parent Alphabet has pulled back on plans to roll out Fiber to new markets, cut staff at Fiber and stopped offering TV service in some markets, making it a broadband-only offering. Last summer, around the time Google Fiber acquired Webpass, it began exploring whether wireless was a more cost-effective option than digging up streets to lay fiber optic cables.