Jessi Combs, who was known as the "Fastest Woman on Four Wheels" to race fans and fans of TV's MythBusters, has died at the age of 39 after a "horrifying" car crash in Oregon.

E! News reports that Combs was attempting to break a land speed record when she suffered a one-car accident in the Alvord Desert in the southern part of Oregon on Tuesday (Aug. 27). The Harney County Sheriff's Office received a report that a jet car had crashed, resulting in one fatality.

A member of Combs' team, Terry Madden, turned to Instagram on Wednesday (Aug. 28) to confirm that Combs had died in the crash. According to Entertainment Weekly, Madden was also Combs' romantic partner, and the tone of his message bears that out.

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"I have never loved or been loved by anyone as much as this amazing woman @thejessicombs she was truly my unicorn and I enjoyed every single minute that I had with her," he writes. "She was the most amazing spirit that I have ever or will ever know. Unfortunately we lost her yesterday in a horrific accident, I was the first one there and trust me we did everything humanly possible to save her!!"

"I made her a promise that if this didn’t go well that I would make sure and do good with it," he adds, asking fans not to believe anything they read in the news until the family has a chance to comment. He asks fans not to donate to any funds in her name until the family has a chance to direct them to the proper foundation, adding that someone had already tried to profit off her death by selling him a video.

According to E!, officials have also confirmed that Combs died in the crash. The cause of the accident has not been confirmed. Entertainment Weekly reports that Combs died while trying to break her own previous land speed record of 398 mph, which she set in 2013.

In addition to her racing fame, Combs also hosted Discovery's MythBusters from 2009-2010 while Kari Byron was on maternity leave. Her other TV credits included Velocity TV's Overhaulin', Spike TV’s Xtreme 4×4, and a guest appearance on Jay Leno's Garage. She also hosted All Girls Garage.

Reuters reports that Combs' family remembered her as a "dreamer" who was not afraid to follow her passions in a statement, saying, "Jessi’s most notable dream was to become the fastest woman on Earth, a dream she had been chasing since 2012. Combs was one of the rare dreamers with the bravery to turn those possibilities into reality, and she left this earth driving faster than any other woman in history.”

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