Rally driver and YouTube star Ken Block killed in snowmobile accident

American motor-sport legend and YouTube star Ken Block has died in a snowmobile accident in Utah at the age of 55.

A competitive rally driver in series such as Rally America and Global Rally-cross, he earned wide renown later in life for his "Gymkhana" video series on YouTube.

The 10-part series, in which he performed daring racing feats, earned him nearly two million subscribers.

Block also co-founded the skate-wear clothing brand DC Shoes.

Hoonigan Industries, another clothing company he owned, confirmed its founder's passing in a statement on Instagram on Monday.

"Ken was a visionary, a pioneer and an icon. And most importantly, a father and husband. He will be incredibly missed."

Block was riding a snowmobile up a steep slope in Wasatch County, Utah, when the vehicle upended, landing on top of him, the local sheriff's office wrote on Facebook.

He was pronounced dead at the scene from the injuries he sustained.

The news of his death emerged a day after US actor Jeremy Renner sustained serious injuries while using a snow plough to clear snow outside his home in Nevada.

Jeremy Renner still in intensive care after surgery

The sheriff's office in Utah said that Block had been riding with a group but was alone when the crash occurred.

A competitive rally driver since 2005, Block was Rally America's Rookie of the Year in his first season and went on to win rallycross medals at the X Games and podium finishes at the World Rallycross Championship.

He also competed in other actions sports, including motocross, skateboarding and snowboarding.

But Block found a second wind on YouTube, where millions watched him navigate dangerous tracks and obstacle courses in a range of vehicles.