(CNN) -- A snowmobiler remains in critical condition after an accident at the X Games Aspen, his family said Monday.
Caleb Moore, 25, was competing in the snowmobile freestyle final Thursday in Aspen, Colorado, when he came up short while trying to do a back flip. The front skis of the machine clipped the landing hill and Moore shot forward over the handlebars. The 450-pound snowmobile struck him as he slid down the hill and the machine tumbled over him.
"The Moores want to express their gratitude to all of Caleb's fans, friends and family for their strong support and ask for continued prayers in the coming days," the snowmobiler's family said in a statement.
St. Mary's Hospital didn't immediately respond to CNN's inquiry into Moore's condition.
The family statement said Moore was being "closely monitored."
Moore's brother Colten also was involved in an accident during Thursday's event. He was released from the hospital Saturday, according to his Facebook fan page.
Colten Moore encouraged fans to pray for his brother.
"We continue to fight and pray for him," he wrote on Facebook.
The X Games Aspen features competitors in snowmobiling, snowboard and skiing events.