The notorious Khumbu Icefall is the first and most dangerous section of the standard South Col route to the summit of Mount Everest. Here we discuss what the Icefall is, why it is so dangerous, and what happens to those caught within its crushing embrace.
What is the Khumbu Icefall?
The Khumbu Glacier is a ten mile (17 km) river of ice that starts from snowfields high on the Lhotse Face at about 25,000 feet (7,600m). It is the highest glacier on Earth. This glacier carves out the valley of the Western Cwm for two miles, then falls over a steep section of underlying rock between 19,500 feet (5943m) and 17,300 feet (5270m). This is the Khumbu Icefall.
Basically it’s a glacier falling over a cliff.
The torrent of ice that is the Khumbu Icefall moves at about 3 to 4 feet (0.9-1.1m) a day, fast for a glacier, and as a result chunks of ice the size of tower blocks are constantly on the move: toppling over, subsiding into crevasses, and bursting into a million pieces.

The only way up Mount Everest’s “easy” route is through this slow white maelstrom of death.
I have been through the Icefall several times, once alone, and I nearly came to grief in there on three occasions: once by an avalanche, once by falling down a crevasse, and once when on top of a collapsing section of Icefall.
Fascinating Facts about the Khumbu Icefall
The Khumbu Icefall fascinates people because it’s one of the most dangerous places on Earth. Here are some fascinating facts about the Khumbu Glacier and Icefall:
1. The Khumbu Glacier is the Highest in the World – But It’s Melting Fast
Because the sides of the Khumbu glacier are almost at a standstill and the centre is moving so fast, huge crevasses form, some over 150’ (45m) deep, together with tottering ice seracs over 50 feet (15 m) high.
Despite its size, due to climate change the Khumbu Glacier is estimated to be retreating about 65’(20m) each year and has shrunk about 3,100 feet (940m) between the 1960s and 2001.
2. The Khumbu Glacial Melt is Making Everest Base Camp Lower
Everest Base Camp is lower today due to the Khumbu glacier ice melting.
In 1953 when Hillary and Tenzing summited, Everest Base Camp was at an altitude of 17,454’ feet (5320m); today it’s 17,322 feet (5280m).
3. The Sherpas Who Work in the Khumbu are Called Ice Doctors
Sherpas in the Icefall work hard all climbing season long to put in and maintain the long ladders and ropes used by the paying clients. They are known as the Ice Doctors. As a result, they are exposed to far more danger than the clients, who only pass through a couple of times.
It’ s a dangerous place to work. At around 6:30 am local time on 18 April 2014, 16 Sherpas were killed by a huge avalanche in the Icefall. Only 13 bodies were recovered (source: CBC)
4. There’s a High-Altitude Cough Named After It
The hacking dry cough suffered by clients and Sherpas alike is called the Khumbu Cough.
Symptoms of the Khumbu cough are, naturally, a persistent hacking cough, but also a runny nose and the expulsion of clear phegm. The Khumbu cough is caused by the dry air of high altitude which irritates the lungs and airways, and can last as long as you’re at high altitude.
My friend Dave actually broke a rib with this violent cough, and summited with the fracture. The best treatment is to moisten the air: wear a buff over your mouth, suck on throat lozenges, avoid over-exertion which leads to over-breathing and hydrate, hydrate, hydrate!
5. You Can’t Avoid the Icefall When Climbing Everest’s South Side
To date, every climber who wants to summit Everest from the Southern (Nepali) side must pass through the Icefall – which is why the Sherpas there work so hard to make it safer.
A route closer to the Nuptse side has been proposed. However, avalanches regularly sweep down that southern wall of the Western Cwm, so it is not much safer.

Khumbu Icefall Bodies: Why is the Icefall so Dangerous?
The Khumbu Icefall is so dangerous because three of the most lethal events on Everest can happen there. These are avalanches, ice collapses and falls into crevasses.
It’s why there are so many bodies there, too – it’s also too dangerous to retrieve bodies from such a precarious spot (for more on this, see why bodies aren’t removed from Everest).
There have been at least 45 deaths recorded within the Icefall. These have been caused by:
- Avalanche onto the Icefall: 22 deaths or 49%
- Collapse of ice: 15 deaths or 33%
- Falling into a crevasse: 6 deaths or 13%
- Falls: 1
- Acute Mountain Sickness: 1
Oddly enough I have personal experience of the first three types of Icefall accident.
Firstly, I was involved in an avalanche with Brian Blessed near Camp 1 in 1993 (see Top 10 Ways People Die on Everest (The Dangers)).
Then on another occasion I was descending the Icefall, stepped on a patch of snow between two ice blocks and fell straight through into a bottomless hole. One minute I was in bright sunlight, the next I was swinging on the thin rope in a huge bottle-green crevasse.
My friend Steve Bell saved me: he held hard onto the rope with his ice axe while I scrabbled up the sides with my crampons. I remember the chips of ice falling past but never heard them hitting the bottom.
Then in 2007, as we approached the top of the Icefall one of my companions clipped into the fixed ropes. At that moment a huge block of ice fell off in front of us with a roar and a cloud of white ice smoke.
It was no more than two metres from us, it took out a whole section of ropes, and my heart sank; of all days to have to start abseiling down the bloody Icefall! Ten seconds later and it would have killed all of us.

Although it’s the most dangerous section on the South route, the Icefall may be getting safer due to shrinkage. Everest guide Russell Brice said:
“On Everest looking at photos from above, it seems that the Icefall between BC and C1 is actually getting easier and arguably safer.
It also seems that several of the hanging glaciers above the Icefall are now leaning back and seem to be less active than what we experienced in 2012, again this can be explained by the warm [er] temperatures at this altitude.”
Russell Brice (source: Alanarnette.com).
How Fast is the Khumbu Glacier Melting and Moving?
As we have seen, the glacier moves at about one metre a day. It visibly changes every day. Because of climate change, it is estimated to be retreating about 65 feet (20m) each year and has shrunk about 3,100 feet (940m) between the 1960s and 2001.
In 70 years of occupation, Everest Base Camp has decreased in altitude about 130 feet as the glacier has shrunk.
Can You Trek to the Khumbu Icefall?
It is possible to trek to the Khumbu Icefall. Base Camp is situated just below the Icefall, but it is inadvisable for unequipped trekkers to start climbing the great waves of ice that begin the icefall.
You would need a climbing permit, a harness, crampons, ice axe, a jumar (ratchet device), an abseil device and some training. You’ll realise why if you read the next part…
What It’s Like to Climb Through The Icefall
The following excerpt is from my diary of the 2007 expedition:
“You start from your tent at Base Camp just after dawn and put your crampons on as soon as the bare ice starts. Then, puffing hard in the thin air, you start climbing up and down the frozen waves of ice.
You skirt round little ponds and haul yourself up icy crests. Soon you are jumping over small crevasses in the ice, and then you will encounter your first ladders.
Balancing over four ladders tied together across a bottomless crevasse is a nerve-wracking experience. Then the fixed ropes start. These are woven up the Icefall by a group of Sherpas, the ‘Icefall Doctors’.
The thin white ropes are attached to the ice by stakes and ice screws, and the idea is to clip yourself in as a sort of extreme stair-rail. If you fall off the ladder they might hold you.

After the four ladders, there is a collapsed section of ice we are calling Popcorn Alley, because the metre-wide blocks do look like a vast popcorn spillage down some giant staircase.
It is very hard to find anything solid to stand on in here. After this is The Hammer, a 50-tonne beam of cracked ice bridged across the route.
As you try to rush under this you try not to think that one day soon it is going to fall. Unfortunately, some joker has put a knot in the fixed rope right under the Hammer so you come to a twanging halt and have to unclip, then re-clip on the other side of the knot.
After this comes Happy Valley, a collapsed section of such terrifying insecurity you only dare whisper to your companion for fear of dislodging the tottering blocks around you. Some are extraordinarily like blocks of ice cream, except that they are the size of a house. Other parts of the ice are exactly like a Fox’s Glacier Mint: hard and transparent.
Climbing as quickly as we could in air that contained only half the amount of oxygen at sea level we eventually came up to the Great Slices: the top of the Icefall. Here we relaxed a bit, but Camp I was still hours away. Base Camp radioed a warning of bad weather, so we pulled extra clothes on and climbed up into a snowstorm.
As we got out of the Icefall the terrain flattened out and we entered the Western Cwm, the huge valley under the peak of Everest. We trudged along in the whirling snow, alone with our thoughts. Eventually, ten tents loomed through the mist and we threw our gear into one of them.
We dragged food out of the store tent and started melting ice to drink. One by one the rest of the climbing team came in to camp after us.
After my worst night for years (the mats were hard and my sleeping bag soaked), we descended back to Base Camp. Running as fast as we could we got down in two and a half hours – half the time it took to come up. The Icefall is not a place in which to linger.”
The Discovery of the Khumbu Icefall: Its History
On 19 July 1921 two human figures came into view on a high saddle between the mountains of Pumori and Lingtren. They were the first humans to gaze up the great valley to the south of Mount Everest.
George Mallory and Guy Bullock, the two British members of the Mount Everest Reconnaissance Expedition saw a great mass of tumbled ice that looked impossible to climb.
“We have seen this western glacier and are not sorry we have not to go up it. It is terribly steep and broken.”
– George Mallory in 1921
That is the first written description of the icefall. (Source: PBS)
Mallory named the great valley “The Western Cwm” after the little hollows or cirques at the heads of the valleys of his beloved North Wales, a thousand of which would fit into their namesake.
He and Bullock swiftly discounted the Icefall as a possible route up the mountain, little knowing that in 100 years thousands of climbers would have gone that way.
The next climber to arrive, after the war in 1950, was the great Bill Tilman, who had been the leader of the 1938 British Mount Everest expedition. After the Chinese invasion of Tibet, the country was now forbidden to Westerners, closing the Northern approaches to Everest.
But Nepal was now open, and so Tilman trekked in to explore the southern possibilities on the mountain. He was therefore one of the very first to examine the terrifying Icefall from close up. He considered it to be passable, but unacceptably dangerous.

Tilman often wrote about icefalls during his great explorations of the 1930s with Eric Shipton, and the name “Khumbu Icefall” almost certainly originated with him.
Then a young English doctor named Michael Ward spent hours at the Royal Geographical Society (RGS) where he found uncatalogued photos, an unpublished map (ca. 1937), and footage from an RAF Mosquito which had overflown the summit during the war.
He thought he saw a route through the Icefall and this, in turn, encouraged him to organise a proper reconnaissance of the southern route in 1951 (source: HimalayanClub).
And so it was that on on 4 October 1951 the expedition leader Eric Shipton, Tom Bourdillon and two young New Zealanders called Earle Riddiford and Edmund Hillary, with three Sherpas finally tackled the Icefall. They got to 30 feet (9 m) below the crest of the icefall when a small avalanche made Shipton decide to turn back. He felt it was unfair to the less experienced Sherpas to expose them to such risks.
Ed Hillary had been nervous about meeting Eric Shipton, then the most famous living mountaineer in the world. He hastened into the dining room at Dingla, worried that his colonial dress standards might not be high enough for the English:
“As we came into the room, four figures rose to meet us. My first feeling was one of relief. I had rarely seen a more disreputable bunch, and my visions of changing for dinner faded away for ever”. (source: wikipedia)
As we now know, the 1953 British Mount Everest expedition succeeded in climbing through the Icefall and put Ed Hillary and Tenzing Norgay Sherpa on the summit. Since then thousands of climbers have passed through the Icefall, but dozens have died in there. It was – and still is, one of the most dangerous places in the world.