(Updates with identity of man killed)
By Keith Coffman
DENVER, Jan 7 (Reuters) - The 24-year-old grandson of the founder of the Vail Mountain ski resort was killed and three others suffered minor injuries on Tuesday when a large avalanche swept them down a mountain outside the resort, officials said
Tony Seibert, grandson of Vail founder Pete Seibert, died in the avalanche about 11:30 a.m. local time in an area known as East Vail Chutes that lies just outside the boundary of the resort, Eagle County Coroner Kara Bettis said.
Bettis said the cause of his death would be determined in an autopsy.
Three other people who were skiing or snowboarding in the same area were also caught in the wave of snow and were treated for minor injuries, the Eagle County Sheriff's Office said in a written statement.
The Colorado Avalanche Information Center said in a Twitter post that the avalanche was large and occurred near a tree line on a slope.
The avalanche comes less than a year after five backcountry snowboarders were killed in an avalanche in April 2013 at Colorado's Loveland Pass, 48 miles (77 km) west of Denver.
The avalanche danger in the Vail area on Tuesday was rated as "considerable," due to high winds and recent heavy snows, said Spencer Logan, forecaster with the Colorado Avalanche Information Center.
This avalanche death was the second such Colorado fatality this winter season, and the fifth nationwide, Logan said.
Pete Seibert, who survived a combat injury in World War II to become a competitive skier, opened the ski resort at Vail in 1962. He died in 2002 at the age of 77. (Writing by Alex Dobuzinskis and Dan Whitcomb; Editing by Cynthia Johnston, Cynthia Osterman and Ken Wills)