A former University of Colorado student who survived being kidnapped by Colombian guerrillas in 2003 is now missing on Mount Rainier.Mark Wedeven, 29, of Olympia, Wash., was one of 11 climbers hit by an avalanche Saturday while taking the direct route on Mount Rainier's Ingraham Glacier, according to the Boulder Daily Camera newspaper.The slab avalanche occurred at the 12,500-foot level as a large plate of snow broke away from the mountain, said Mount Rainier National Park spokeswoman Patti Wold.Ten of the trekkers were pulled from the snow by mountaineering guides but the other person couldn't be located, she said. The 11th person, Wedeven, may have been climbing alone."The missing climber did not register for his climb," mountaineering ranger Stefan Lofgren said.Park officials assumed their search would be a recovery -- not rescue -- mission as Wedeven was believed dead, Mount Rainier National Park spokesman Kevin Bacher told the newspaper.Wedeven studied English at CU-Boulder, according to the Daily Camera.Wedeven's parents told KIRO-TV they believe their son died quickly in the early-morning avalanche Saturday doing what he loved. Wedeven, the father of a 5-year-old boy, had scaled Rainier numerous times, his parents said.Wedeven's mother, Carol, told a TV station, "He said to me, 'Mom, if I die on a mountain, don't worry about it,' and I'm sure it was instant and it was over."Wedeven was briefly kidnapped in January 2003 by Colombian rebels. The newspaper reported that it happened while Wedeven was hiking in Central America as part of an independent study program.