Vehicle builder, racer, and TV personality Jessi Combs has died in a crash attempting to break a land-speed record in southeast Oregon.

The 39-year-old was driving the jet-powered North American Eagle Supersonic Speed Challenger at the time. Combs had held the title for ‘fastest woman on four wheels’ when she reached 398 mph (640 km/h) in the same land speed vehicle back in 2013.

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Eager to ultimately exceed 512 mph (823 km/h) to become the ‘Fastest Woman on Earth’, Combs piloted the car through to 483.227 mph (787.334 km/h) during a shakedown run in October 2018 and came to Oregon determined to set a new record.

Limited details about the fatal accident are known but the Harney County Sheriff’s Office says it is investigating the crash which occurred on a dry lake bed roughly 90 miles south of Burns, Oregon. Combs’ partner Terry Madden described it as an “horrific accident” and said he “did everything humanly possible to save her.”

Combs made a name for herself after starring on various automotive TV shows include Overhaulin’, Truck U, Two Guys Garage, All Girls Garage, and Xtreme 4×4. She was also a host and builder on a season of Mythbusters.

“I’m so so sad, Jessi Combs has been killed in a crash,” former Mythbusters host Adam Savage wrote on Twitter. “She was a brilliant & too-notch builder, engineer, driver, fabricator, and science communicator, & strove every day to encourage others by her prodigious example. She was also a colleague, and we are lesser for her absence.”