One person was killed in an avalanche at the Arapahoe Basin (search) ski area Friday, Summit County Undersheriff Derek Woodman said.

The victim's name and hometown were not immediately released.

The avalanche, 800 feet long and 1,000 feet wide, occurred at about 10:30 a.m. on a ski run at the resort.

The run was closed to skiers at the time, but other runs were open, authorities said.