Story highlights The "Swiss Machine" was killed in a mountaineering accident

He planned to climb 8,850-meter Mount Everest in May

(CNN) Swiss climber Ueli Steck was killed Sunday in an accident near Mount Everest, Nepal's tourism department said.

The 40-year-old died when he slipped from a slope and fell into a crevasse at around 6,600 meters on Mount Nuptse, expedition organizers told CNN.

His body has been recovered and airlifted to Lukla, where the nearest airport to Mount Everest is located, Dinesh Bhattarai, of the Nepal Tourism Department said.

The "Swiss Machine" was acclimatizing himself as he planned to ascend 8,850-meter Mount Everest and Mount Lhotse next month, Mingma Sherpa, an official with expedition organizer Seven Summit Treks said.

"Quick Day from Basecamp up to 7,000m and back. I love it is such a great place here. I still believe in active aclimatisation. This is way more effective then spending nights up in the altitude," Steck wrote on Facebook last Wednesday.

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