One person was killed and three others were trapped and injured today in a large avalanche in the back country terrain east of Vail ski resort in Eagle County, Colo.

Anthony (Tony) Seibert, 24, of Boulder and Vail died in today's avalanche, the Eagle County coroner confirmed. Seibert is the grandson of Pete Seibert Sr., who is one of the people credited with discovering the terrain that would become Vail Mountain.

The slide happened at about 11:30 a.m., according to Eagle County Sheriff spokeswoman Jessie Mosher.

Search and rescue teams responded to the area of the avalanche, which started near the treeline, the Colorado Avalanche Information Center reported.

At least four people were trapped, the center said. Three were rescued with nonlife threatening injuries, Mosher said.

The age, sex and identities of the victims were not immediately available.

The avalanche occurred outside the boundary of the Vail Ski Resort in an area called the East Vail Chutes, officials said. It happened in the same back country area where Edwin LaMair was briefly buried alive after triggering an avalanche on Dec. 22. His brother Davis recorded dramatic video as he skied to Edwin's rescue.

Today's avalanche fatality in Colorado is the fifth in the U.S. this season, according to the Colorado Avalanche Information Center. On average, the center says 28 people are killed in avalanches every year.