Jan. 31, 2013 -- Texas snowmobiler Caleb Moore died today after succumbing to injuries he sustained one week ago at the Winter X Games in Aspen, Colo., when his snowmobile flipped on top of him in a violent crash during competition.

"This morning Caleb Moore passed away," the Moore family said in a statement through family spokeswoman Chelsea Lawson. "He will be truly missed and never forgotten.

"The family wishes to express their deep gratitude for all the prayers and support they have received from all the fans, friends and family around the world that Caleb has inspired."

This is the first death as a result of a competitor's sustaining injuries during competition in the 18-year reign of the X Games, which is produced by ABC's sister network ESPN.

ESPN today released a statement offered condolences to the Moore family and saying it would conduct a "thorough review" into the X Games freestyle snowmobiling event and "adopt appropriate changes" for future X Games.

"For 18 years, we have worked closely on safety issues with athletes, course designers and other experts," network officials said, adding that Moore was hurt performing a move he had done several times before. "Still, when the world's best compete at the highest level in any sport, risks remain."

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Scott Guglielmino, ESPN's senior vice president of programming and global X events, said in an interview today on ESPN's "Outside the Lines" that X Games officials followed all medical protocol in treating Moore on site.

While "trying to mitigate as much risk as possible" is their top concern, Guglielmino said, the "world class" athletes that compete in the event understood the risks. He said competitors also have to provide proof they can perform their tricks before they are allowed to compete at the X Games.

"We are not equally responsible but we are all responsible for [Caleb's accident]," Guglielmino said.

Moore, a 25-year-old former all-terrain vehicle racer and medaled X Game competitor from Krum, Texas, had been in critical condition at St. Mary's Hospital in Grand Junction, Colo., after developing complications in his heart and brain after an accident last Thursday night during the Snowmobile Freestyle finals.

Moore was completing a back-flip when he came up short and the skis on his sled hit the landing, causing the 450-pound machine to flip end-over-end.

Moore went over the handlebars of the snowmobile and it came crashing down on top of him. He tumbled down the slope for several feet before coming to a stop at the bottom, where he lay on the ground for a few minutes.

Moore eventually got up and walked off the course with help, but he was rushed to Aspen Valley Hospital with a concussion, according to an X Games Medical report. While there, doctors discovered bleeding around Moore's heart and he was flown to St. Mary's Hospital.

St. Mary's Hospital declined ABC News' request for comment.

Moore underwent emergency heart surgery last Friday and had since remained in intensive care. But on Sunday, the Moore family released a statement through ESPN saying, "his cardiac injury has led to a secondary complication involving his brain."

Moore's younger brother Colten Moore, 23, also competed in the Snowmobile Freestyle finals and crashed during the X Games competition. He was taken to the hospital with a separated pelvis but was released Friday and "will not require surgery," according to Lawson.

An online fundraiser was set up on behalf of the Moore family on Tuesday to help the family pay for medical bills. As of this writing, the fund had raised over $26,500.

Jackson "Jacko" Strong, Moore's fellow X Games snowmobile competitor, is also auctioning off his 2012 Polaris IQ 600R snowmobile, which he rode in competition at this year's X Games, to help benefit the Moore family.

Strong also crashed during last week's X Games competition. During his Best Trick snowmobile run, the 21-year-old Australian native let go of the handlebars and attempted to grab the back of the sled in a midair stunt, but couldn't get a good grip and flew off of it. The snowmobile landed on its skis and raced into the crowd watching on the sidelines. No one was seriously injured.

Both Moore brothers are decorated Winter X Games veterans, who made their debut in competitive snowmobiling in 2010 in Aspen after years of racing ATVs.

Caleb, who has four Winter X Games medals, took home the bronze medal in Snowmobile Freestyle at last year's games, and stood next to brother Colten on the podium, who had snagged gold.