The Khumbu Icefall is an icefall

Icefall

An icefall is a portion of some glaciers characterized by rapid flow and a chaotic crevassed surface. Perhaps the most conspicuous consequence of glacier flow, icefalls occur where the glacier bed steepens and/or narrows...

 at the head of the Khumbu Glacier

Khumbu Glacier

The Khumbu Glacier is located in the Khumbu region of northeastern Nepal between Mount Everest and the Lhotse-Nuptse ridge. With elevations of at its terminus to at its source, it is the world's highest glacier. The Khumbu Glacier is followed for the final part of the trail to Everest Base Camp....

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The icefall is found at 5486 metres (17,998.7 ft) on the Nepal

Nepal

Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...

i slopes of Mount Everest

Mount Everest

Mount Everest is the world's highest mountain, with a peak at above sea level. It is located in the Mahalangur section of the Himalayas. The international boundary runs across the precise summit point...

 not far above Base Camp

Everest Base Camp

There are two base camps on opposite sides of Mount Everest. South Base Camp is in Nepal at an altitude of , and North Base Camp is in Tibet at ). These camps are rudimentary campsites on Mount Everest that are used by mountain climbers during their ascent and descent...

 and southwest of the summit. The icefall is regarded as one of the most dangerous stages of the South Col

South Col

The South Col usually refers to the southern col between Mount Everest and Lhotse, the first and fourth highest mountains in the world. When climbers attempt to climb Everest from the southeast ridge in Nepal, their final camp is situated on the South Col...

 route to Everest's summit. The Khumbu glacier that forms the icefall moves at such speed that large crevasse

Crevasse

A crevasse is a deep crack in an ice sheet rhys glacier . Crevasses form as a result of the movement and resulting stress associated with the sheer stress generated when two semi-rigid pieces above a plastic substrate have different rates of movement...

s open with little warning. The large towers of ice or serac

Serac

A serac is a block or column of ice formed by intersecting crevasses on a glacier. Often house-sized or larger, they are dangerous to mountaineers since they may topple with little warning...

s found at the icefall have been known to collapse suddenly. Huge blocks of ice tumble down the glacier from time to time; they range in size from cars to large houses. It is estimated that the glacier advances 3 to 4 ft (0.9144 to 1.2 ) down the mountain every day.
Since the structures are continually changing, crossing the Khumbu Icefall is extremely dangerous. Even extensive rope and ladder crossings cannot prevent loss of life. Many people have died in this area, such as a climber who was crushed by a 12-story block of solid ice. Exposed crevasses may be easy to avoid, but crevasses buried under snow can form treacherous snow bridge

Snow bridge

Snow bridge is an arc across a crevasse, a crack in rock, a creek, or some other opening in terrain. It is typically formed by snow drift, which first creates a cornice, which may gradually grow to reach the other side of the opening.-Dangers:...

s through which unwary climbers can fall.