PORTLAND, Ore - Jet-car speed racer Jessi Combs, known by fans as the "fastest woman on four wheels," has died in a crash in Oregon's Alvord Desert while trying to break a speed record, local authorities said Wednesday.

Combs, 39, died Tuesday afternoon while racing in a dry lake bed in a desert in remote Harney County, sheriff's Lt. Brian Needham said in a statement. The cause is under investigation.

Terry Madden, Combs' teammate on the North American Eagle racing team, said in an Instagram post Wednesday that he was heartbroken and added a video collage of photos and video clips of Combs with various team members.

"She was the most amazing spirit that I have ever or will ever know," Madden wrote. "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!!"Combs was widely known in the niche sport of jet-car racing and was attempting to break the Women's Land Speed Record of 512 mph (823 kph) set in 1976 by Kitty O'Neil when she died. Jet cars are race cars propelled by jet engines.

She currently held the record as the fastest woman on four wheels — O'Neil piloted a three-wheeled vehicle — for a 398 mph performance in 2013 and had driven even faster in follow-up runs, but mechanical problems prevented those from making the record books.

In an Instagram post on Sunday, Combs indicated that she hoped to break O'Neil's record in the Oregon desert.

She wrote, "People say I'm crazy. I say, 'thank you.'"In a statement, Combs' family said her "most notable dream was being the fastest woman on Earth."

Combs, who was born in Rapid City, South Dakota and lived in Long Beach, California, dabbled in snowboarding earlier in life and was also an accomplished artist and craftswoman, according to a biography on North American Eagle, her racing team.

The Alvord Desert is an extremely remote and sparsely populated region in southeastern Oregon, about 400 miles (643 kilometers) southeast of Portland.

AP