Grieving friends and loved ones are using social media to share remembrances of the late Erik Roner, extreme athlete and star of MTV's "Nitro Circus."

The skydiver, motocross stuntman, BASE jumper and professional skier died yesterday morning following a tragic skydiving accident at a charity golf tournament in Olympic Valley, California. He was a member of the Nitro Circus Crew, which was documented for two seasons on MTV and spawned a live world tour plus “Nitro Circus: The Movie," a 3D feature film. Roner leaves behind a wife Annika and two children.

Among the many paying tribute: Parks Bonifay, Roner's former "Nitro Circus" co-star.

"I Love you brotha, you will be missed! Thanks for all you did Erik Roner. My thoughts and prayers got out to his Wife Annika and they're kids," wrote Bonifay, who shared the above photo of the adventurer on Instagram. "To say we just lost a good one yesterday would be an understatement! Erik was ALLTIME! Seriously one of the most funny humans I've known. Erik pushed the boundaries on what ever you could possibly think of. Still trying to wrap my head around that he is gone ... I'll miss you forever my friend, thanks again for the many smiles you gave! #legend"

Meanwhile, Dave Mirra posted the above shot of Roner, writing, "I had the pleasure of shredding the animal house with @erikroner a few years back when nitro circus came to Greenville. So sad to hear he was in a tragic accident today. We're praying for his family. Rest in peace Erik and thanks for putting it on the line every time you've entertained us."

"Nitro Circus" castie Jolene Van Vugt posted a shot of the pair during happier times. "I can't find the words... Heartbroken from the shocking loss of this amazing being. So unbearably missed already you are, Roner. Rest in peace my dear friend OX #RIP"

In addition, the following tributes have been posted:

If you'd like to offer your own memorial to Roner, please do so in the comments section. And, to remember his fearless, high-flying ways, watch the video below. In it, Roner tied 90 helium balloons to a lawn chair (recreating a scene from the Pixar film "Up") so that he could take to the sky: