The man who fell from near the snowy summit of the 11,000-foot (3,353-meter) mountain in northern Oregon was airlifted to Legacy Emanuel Medical Center in Portland, where he was pronounced dead on arrival, said Brian Jensen of the Clackamas County Sheriff's Office.
By the time rescue crews arrived, the man was bleeding, had injuries to his face and his respiration was on and off, the Oregonian newspaper reported, citing state search and rescue coordinator Scott Lucas.
Two other groups of climbers spent much of the day stranded high on the slopes due to dangerously unstable conditions, but were slowly making their way down the mountain by about 5 p.m, Jensen said.
A group of four people, which included a climber who had been hurt and was having difficulty walking, was being assisted by rescuers. A group of three other people was descending on their own.
Randy Lee, 44, was descending from near the summit shortly before noon when he met a group of climbers who said their companion had just fallen some 1,000 feet.
"They said he tumbled. They said it looked like he was doing cartwheels," Lee told Reuters.
Lee said one of the four remaining climbers descended to the injured man, and shortly afterward another member of the party fell several hundred feet and suffered minor injuries.
Major Chris Bernard of the Air National Guard's 304th Rescue Squadron said that the mountain, Oregon's highest peak, turned deadly when cold overnight temperatures warmed quickly during the day, causing ice and rock to break loose.
"It was a great climbing scenario last night on Mount Hood and it just turned bad," Bernard said.
Jensen said it was possible there were more people on the mountain who had not been in communication with authorities.
A 40-person rescue crew, assisted by Air National Guard crews, was working to get everyone to safety before a storm hit later on Tuesday or early on Wednesday.
An estimated 8,000 to 10,000 climbers from around the world each year try to scale Mount Hood, an 11,249-foot-tall (3,429-meter) peak in the Cascade range. Since 1883 more than 100 people have been killed on the mountain, according to the Oregonian.
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