Casey was riding the bike at about 2:30 p.m. on the track, known as “the Slayground” in Ramona, Calif., when he lost control and was thrown, the San Diego County medical examiner’s office said.

Bystanders called 911, but Casey had no pulse when paramedics arrived, the examiner’s office said. Paramedics tried advanced cardiac life-support measures but he could not be resuscitated.

While Casey was known for his BMX riding, he was riding a motorcycle when he crashed, sheriff’s Lt. Daniel Vengler said.

California Highway Patrol Officer Jared Grieshaber said Tuesday that Casey had attempted to perform a jump but missed the landing.

Pat Casey competes in the BMX Dirt qualifier event of the ESPN X Games at U.S. Bank Stadium on July 20, 2018, in Minneapolis, Minn.

(Sean M. Haffey / Getty Images)

Casey, who lived in Riverside, was married and the father of two elementary school-age children.

According to a bio of Casey posted on the Vans company website, Casey went pro by the time he was 16 and bought a house at the age of 18, where he created a ramp and trails in the backyard known as “The Dreamyard.”

“Pat’s daily sessions are on a level that few will ever touch,” the company said, recalling how he learned on a 6-foot-tall mini ramp his father built in his backyard when Casey was 12.

Casey was the first rider to successfully execute elaborate bicycle motocross stunts called the “decade backflip” and “double decade backflip” in competition, according to news accounts.

Many took to social media to post tributes to Casey, who won medals at the X Games in 2012 and 2013, and won his first gold medal from the games in 2021.

On its Instagram page, X Games said it was “deeply saddened” by his death.

“A true legend in the action sports community, Pat will always be a member of the X Games family and an inspiration to everyone’s life he touched,” the post reads.

BMX rider T.J. Lavin, who hosts MTV’s “The Challenge,” posted a picture of Casey on his Instagram page.

“The world lost one of the baddest to ever do it,” Lavin wrote. “I’m so sorry for his wife and kids. @patcaseybmx will forever be remembered for the down to earth sweetheart of a guy that he was. #bmxfamily”

The Ramona track is owned by motocross and supercross racing star Axell Hodges, the San Diego Union-Tribune reported in 2021. It was one of the three sites hosting the X Games in 2021. Casey also hosted part of the games that year at his Dreamyard track.

The Slayground also hosted X Games motocross events last year.

City News Service contributed to this report.