Caleb Moore is the snowmobile star who was just seriously injured at this year's Winter X Games.
We previously mentioned that he mistimed a big air backflip and brought his 450-pound snowmobile down on top of himself!
Originally, it was only thought he had a concussion until he had to be rushed to a nearby hospital for bleeding around his heart.
Sadly, things are even more serious. He is currently in critical condition after a secondary complication involving his brain.
Caleb's grandfather said that the prognosis isn't good. He said it's "almost certain" that Caleb won't recover.
That's so awful! He's only 25.
We hope he makes a miraculous recovery!
Check out the video (above) to see his violent crash at this year's Winter X Games.