A US climber has died after descending from Everest, officials said Tuesday, taking this season’s toll to 11 including several deaths blamed on overcrowding on the world’s highest mountain.

American Christopher John Kulish, 61, had already climbed the 8,848-metre (29,029-feet) peak, and was safely back at a camp below the summit on Monday evening.

“All of a sudden he had a heart problem and passed away at South Col, according to his expedition organisers,” said Mira Acharya from Nepal’s tourism department.

An Australian climber meanwhile was recovering in hospital in Kathmandu, officials said, after reportedly being found lying unconscious above 7,000 metres (23,000 feet).

The reports said that Gilian Lee from Canberra was attempting to climb the northern flank of Everest from Tibet without supplementary oxygen.

Nepal issued a record 381 Everest permits this season and a short weather window resulted in some teams waiting several hours in the dangerous “dead zone”, running out of oxygen supplies and risking exhaustion.

Source: v.duta.us