(CNN) -- Recovery efforts on Alaska's Mount McKinley were suspended Sunday because of environmental hazards following an avalanche thought to have killed four Japanese climbers, the National Park Service said. The avalanche on the western side of the mountain, America's highest peak, was first thought to have occurred on Thursday, the parks service said Sunday. However, rangers later confirmed with climber Hitoshi Ogi, who survived the avalanche, and with teams on the mountain that the slide occurred early Wednesday. The section where the avalanche took place is roughly 11,800 feet above sea level, park spokeswoman Maureen McLaughlin said Saturday. The five were traveling on McKinley's West Buttress as one rope team, although the rope broke during the incident, officials said. One climber, Ogi, survived the incident after he was swept into a mountain crevasse and was able to climb out, sustaining a minor hand injury, officials said.
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Dangerous conditions prompt a permanent suspension of recovery efforts
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Four Japanese climbers are presumed to have died in an avalanche
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The avalanche took place a day earlier than initially thought, officials say
That fatality was considered @placeholder's first serious incident of the 2012 mountaineering season.