Race car driver and “Mythbusters” host Jessi Combs has died after crashing her vehicle in an attempt to break her own land-speed record. She was 36.

Combs was known as the “fastest woman on four wheels” after setting a record of 398 mph in her jet-powered North American Eagle Supersonic Speed Challenger in 2013. Combs had attempted to beat her record last year, when she managed to get to speeds of 483 mph. A mechanical error ended that attempt.

One of her team members, Terry Madden, announced her death on Instagram.

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“I have never loved or been loved by anyone as much as this amazing woman @thejessicombs,” he wrote. “She was truly my unicorn and I enjoyed every single minute that I had with her. She was the most amazing spirit that I have ever or will ever know.”

Adam Savage, a former co-host on “Mythbusters,” also wrote about Combs. Combs appeared on several episodes of the show when host Kari Byron was on maternity leave.

“She was a brilliant & to[p]-notch builder, engineer, driver, fabricator, and science communicator, & strove everyday to encourage others by her prodigious example,” he said on Twitter. “We are lesser for her absence.”

Combs posted photos of the car she was planning to drive to beat her record days before her death.