Tony Hawk took skateboarding to new heights in 1999 when, high above a halfpipe at the X Games, he began furiously spinning, completing two and a half turns in the air before gliding gracefully back onto the ramp.
The 900 — named for the number of degrees of rotation the move requires — had seemed impossible, but Mr. Hawk, his sport’s biggest star, had landed it, rewriting the rules of what could be done on a skateboard and exposing the sport to a far more mainstream audience.
Then, shortly after his moment of triumph, Mr. Hawk’s form of gravity-defying skating began fading away, nearly to the point of extinction.