Blake Krikorian, a tech entrepreneur and investor who was co-founder and former CEO of Sling Media, has died. He was 48.

According to Recode, Krikorian died Wednesday after apparently suffering a heart attack while surfing in the San Francisco area.

Krikorian and his brother Jason co-founded Sling Media in 2004, which created the Slingbox place-shifting device for watching TV over the Internet. Sling Media was acquired by EchoStar in 2007 for $380 million, which at the time was the parent company of Dish Network.

“As many of you may have heard, yesterday we lost a great man, Blake Krikorian,” Jason Krikorian, who is now a general partner at DCM Ventures, wrote in a post Thursday on Facebook. “My brother. My best friend. My business partner. My mentor. My hero… A beloved friend to so many. I don’t have the words to properly express my feelings, or those of his dear family.”

The Krikorian brothers came up with the concept for the Slingbox after they were frustrated that they couldn’t watch their beloved San Francisco Giants playing when they were on the road. They code-named the product “Lebowski” because of the catchphrase “The Dude abides” in the Coen brothers’ “The Big Lebowski,” given that the Slingbox device adapted the format of the video stream in real time “abiding by what is possible at the time,” Blake Krikorian said in a 2008 interview with UCLA’s alumni magazine. He used the film’s quote in his Twitter profile.

Before Netflix even launched its online-video service, Blake Kirkorian envisioned streaming video everywhere. In 2006, speaking about Sling’s launch of apps for mobile devices and PCs, he said in an interview with the San Francisco Chronicle, “It takes us closer to our overall goal, which is to turn every display that a consumer interfaces with into not only TV or some video source but turn it into the TV that you love the most, which is your living-room TV.”

Sling Media’s technology raised the ire of content owners, including Major League Baseball, which contended the device illegally transmitted its TV programming online (though MLB never pursued litigation). In 2014, Fox Broadcasting filed a legal challenge to Dish’s Sling-based feature, in addition to its lawsuit over the satcaster’s ad-skipping features; after a court ruled Sling technology didn’t violate copyright law, Fox and Dish settled the disputes earlier this year.

“We are shocked and saddened by the tragic news of Blake’s passing. He was a true visionary who forever changed the content landscape when he envisioned the evolution of TV Anywhere over a decade ago with the founding of Slingbox,” Mark Vena, VP of worldwide marketing for Dish’s Sling Media, said in a statement.

As CEO of id8 Group, Krikorian advised companies including Microsoft, AT&T, Toshiba and Time Warner. In 2013, Microsoft named Krikorian corporate VP in its Xbox business unit, following its acquisition of his home-automation startup R2 Studios.

Krikorian served on the boards of Amazon.com and FreeWheel (now owned by Comcast), and was a board partner at VC firm Andreessen Horowitz. He also was an investor in multiple companies, including virtual-reality startup Jaunt, wireless earbud maker Doppler Labs, wearable startup Thync, digital-art startup Depict and online soccer video service FuboTV.

He started his career at General Magic, which created an operating system for mobile devices, and in 1994 he co-founded the Philips Mobile Computing Group where he built and co-led the team created the Velo 1 Windows CE Handheld PC. Krikorian received a bachelor’s degree in mechanical engineering from UCLA.

Krikorian is survived by his wife, Cathy, and their two daughters. His brother Adam Krikorian is head coach of the U.S. women’s national water polo team.