Family spokeswoman Chelsea Lawson, as cited by the Associated Press, says Moore died Thursday morning. He had been staying at a hospital in Grand Junction.
Moore, 25, fell short of a complete rotation while attempting a backflip in the competition and was thrown from his sled. Weighing in at 450 pounds, the riders sled hit the rider upon landing, knocking him unconscious for a brief moment. The X Games athlete walked away from the crash, but was taken to the Aspen Valley Hospital soon after.
According to ESPN, Moore developed bleeding around his heart while at the hospital and was then flown to Grand Junction for surgery Friday.
On Sunday, a family spokeswoman said Moore's injuries include "a secondary complication involving his brain."
"Caleb continues to be monitored in ICU," Chelsea Lawson told The Denver Post on Sunday. "His cardiac injury has led to secondary complication involving his brain. The Moore family thanks all of Caleb's fans and friends for their support and for respecting their privacy."
Caleb’s younger brother, Colten, also crashed in the competition and was taken to the hospital with a separated pelvis, but was released from the hospital after returning to stable condition.
Caleb Moore had been active in ATV/Snowmobile Freestyle Riding in the Winter X Games since 2009 and had accumulated three Winter X medals -- two bronze and one silver.