The Khumbu Icefall: What It Is and Why Climbers Fear It

At night in Everest Base Camp, the ice talks. You hear cracks and low booms coming from somewhere above the tents, and by morning the shape of the glacier has changed a little. That noise is the Khumbu Icefall, a frozen river breaking itself apart as it slides downhill.

Every climber going for the Everest summit from the Nepal side has to cross it, most of them several times. It is the first obstacle above Base Camp and, by the record, the deadliest section of the standard route.

Trekkers ask us about it constantly, and two questions come up more than any others: can I walk on it, and where can I see it from? This guide answers both, along with how the icefall forms, who does the dangerous work of building the route, and what the 2026 season showed about how unpredictable it has become.

We run treks to Everest Base Camp every season, and this is what we tell our clients before they arrive.

What is the Khumbu Icefall?

The Khumbu Icefall is a shattered section of the Khumbu Glacier that sits above Everest Base Camp, running between roughly 5,486m and 6,100m. It gains around 600m of height and stretches about two kilometres.

An icefall forms where a glacier flows over a steep drop in the bedrock beneath it. The ice cannot bend fast enough to follow the slope, so it fractures. What you get is a jumble of towers, blocks and deep splits rather than a smooth surface.

Two features matter here. Seracs are towers of ice, some the size of a small building, that can topple without warning. Crevasses are the gaps between them, and the biggest are over 100m deep and up to 15m wide.

None of it stays still. This section of the Khumbu Glacier moves roughly a metre a day, and a piece of ice takes around four years to travel from the top of the icefall to the bottom. The route through it is never the same twice.

Base Camp itself sits about a kilometre below the icefall at 5,364m, which is why trekkers can get close to it without ever setting foot on it.

How dangerous is the Khumbu Icefall?

The Khumbu Icefall is the most dangerous part of the standard south side route on Everest. The Himalayan Database records at least 47 deaths there between 1953 and 2023.

The danger comes from the ice rather than from the difficulty of the climbing. The technical moves are not hard by mountaineering standards. What makes the section deadly is that a serac can collapse or a crevasse can open at any moment, and no amount of skill or fitness changes that. You are exposed for as long as you are inside it.

Most deaths here come from collapsing ice, not from falls. That is an important difference. A climber can do everything right and still be in the wrong place.

The worst single event happened on 18 April 2014. Seracs on the western spur of Everest gave way at around 6:30 in the morning and swept the route, killing 16 Nepali climbing workers who were preparing it for the season. Nine more were injured, and only 13 bodies were recovered. The spring season was called off.

The following year brought a second disaster. The earthquake of 25 April 2015 triggered an avalanche that hit Base Camp, and afterwards the route-fixing team advised against repairing the way through the icefall. Two consecutive Everest seasons were lost.

There was an earlier tragedy too. In April 1970, a falling serac killed six Sherpas in the same stretch of glacier.

More recently, an icefall collapse in April 2023 killed three Nepali guides at around 5,700m. Their bodies were not recovered. The record makes the pattern clear: this is not a historical danger that modern equipment has solved.

Who takes the biggest risk in the Khumbu Icefall?

Nepali climbing workers do, by a wide margin. A foreign client typically crosses the icefall three or four times in a season. A Sherpa carrying loads and fixing the route can cross it more than twenty times.

That difference is the whole story of the icefall. Exposure is what kills here, and exposure is not shared evenly between the person paying for the expedition and the person carrying the oxygen bottles up to Camp II.

The wider figures say the same thing. Of all the deaths recorded on Everest since the 1920s, more than a third have been working Sherpas, and a large share of those happened in the icefall. In the 2014 disaster, every one of the 16 people killed was a Nepali worker.

We think this is worth saying plainly rather than leaving it in a footnote. The mountain is not equally dangerous for everyone on it. If you want to understand the community that carries this risk, our guide to Sherpa people and culture goes into their history in the Khumbu.

Who are the Icefall Doctors?

The Icefall Doctors are a small team of experienced Nepali climbers who build and maintain the route through the Khumbu Icefall each season. They work under the Sagarmatha Pollution Control Committee, and the team is usually around eight strong.

They go in first, before the commercial teams arrive. In 2026 the team took refresher training at Base Camp in early March with instructors from the Khumbu Climbing Center, held a puja ceremony on 16 March, and began route work the same day.

The job is to pick a line through the maze and then fix it: ropes anchored with ice screws and pickets, ladders laid flat across crevasses, ladders lashed upright against serac walls.

It does not end there. Because the glacier keeps moving, the team goes back in through the season to reset anchors, re-lash ladders and reroute sections that have collapsed. Every expedition on the south side pays a fee that funds this work.

It is some of the most dangerous work in mountaineering, and it is done almost entirely by Nepali climbers whose names rarely appear in summit coverage.

What happened in the Khumbu Icefall in 2026?

The 2026 season was delayed by 19 days because a large unstable serac blocked the route, and it was the clearest recent demonstration of how little control anyone has over this terrain.

The Icefall Doctors had secured a safe passage up to a rockfall point by 8 April. Above that sat a serac roughly 55m long and close to 30m high, cracked through and liable to fall at any time. Work stopped.

The team scouted two alternatives. One would have required erecting ten vertical ladders and routing climbers close to a rockfall zone, which was judged worse than the original line. After several days, they concluded the safest option was still the passage beneath the serac, and waited for the ice tower to come down on its own. Part of it fell. Part of it did not.

The route finally opened on 28 April, when eight Icefall Doctors and 16 guides from expedition operators returned to Base Camp after fixing the way up to the Nuptse face. Eight ladders had been installed across three key sections, with more expected as crevasses widened in the warmth. Climbers were told to report emergencies on radio frequency 144.200.

One new detail stood out this season. Drones were used to supply the route, carrying aluminium ladders and rolls of rope up to Camp I. It is a small change with real consequences, because every load flown is a load nobody had to carry through the icefall on foot.

The delay compressed the season. With more than 400 climbers holding permits and a narrower weather window, the pressure moved from the icefall to the summit ridge instead.

Can you trek through the Khumbu Icefall?

No. Trekkers cannot enter the Khumbu Icefall. The Everest Base Camp trek ends at Base Camp, and going any higher requires a climbing permit and real mountaineering experience.

This is not a rule that gets bent. Above Base Camp you need an Everest climbing permit from the Department of Tourism, a registered expedition operator, and the training to use fixed ropes, ladders and crampons on moving glacier ice. The permit fee alone runs to many thousands of US dollars.

The good news is that you do not need to set foot on it to see it. From Everest Base Camp you stand near the bottom of the icefall, close enough to pick out individual seracs and hear the glacier shifting.

For a wider view, climb Kala Patthar at 5,545m. From there you look across at the whole icefall, the glacier below it and the summit above. Most of our clients say this is the better of the two viewpoints.

See our EBC difficulty guide for what the walk to get there actually involves.

What do the ladders on the Khumbu Icefall look like?

The ladders are ordinary sectional aluminium ladders, lashed together end to end with rope and anchored into the ice at both ends.

They are used two ways. Laid flat, they bridge crevasses too wide to step across, and a single gap can need several ladders joined together. Stood upright, they let climbers get up the vertical face of a serac.

Climbers cross them in crampons, placing the front points and heel between the rungs and moving slowly with a rope clipped in on either side. It is a balance problem more than a strength problem, and almost everyone finds it unnerving the first time.

The number changes every year with the glacier. In 2026 the route opened with eight ladders in place, and the team expected to add more as the season warmed and crevasses widened.

Is climbing Everest from Tibet safer?

Not meaningfully. The north side route from Tibet avoids the Khumbu Icefall entirely, but it is not the safer option. Analysis of the Himalayan Database through 2025 puts deaths per 100 summits at 1.07 on the Nepal side and 1.05 on the Tibet side. The north side trades the icefall for a colder, windier, and more technical upper mountain.

The north side trades the icefall for a longer, more technical and more exposed upper mountain, with a summit ridge that has its own history of fatalities. The risk moves rather than disappears.

For trekkers this is mostly academic, since the Everest Base Camp trek through the Khumbu is a different journey from the drive-in approach to the Tibetan base camp. But it is worth knowing that skipping the icefall does not make the mountain safe.

Is the Khumbu Icefall changing?

Yes. The Khumbu Glacier is thinning and retreating, and the icefall is changing with it.

Research from ICIMOD, the Kathmandu-based mountain research institute, has recorded the glacier retreating and thinning steadily over recent decades, with the icefall itself losing height at a rate measured in centimetres per year. Everest Base Camp sits slightly lower today than it did in 1953, because the ice underneath it has melted.

What that means for climbers is not simple. Some experienced Everest guides have suggested a thinning icefall could become easier to cross over time, while other sections of the route, such as the Western Cwm above it, become the harder problem.

What is not in doubt is that warmer temperatures make the ice less stable within a single season. Crevasses widen faster, snow bridges fail earlier, and the route needs more maintenance. The 2026 delay fits that picture.

Who first climbed through the Khumbu Icefall?

A British reconnaissance team led by Eric Shipton climbed through the Khumbu Icefall in 1951, though they stopped short of the top at a crevasse too wide to cross.

Before that, the icefall was written off. George Mallory saw it from a distance in the 1920s and judged it too steep and broken to be worth attempting, which is part of why early British efforts went to the Tibetan side instead.

A 1950 reconnaissance led by Charles Houston and Bill Tilman reopened the question, Shipton’s team proved a way through in 1951, and by 1953 the icefall was the doorway to the first ascent. Every Everest season since has started here.

When is the Khumbu Icefall at its safest?

It is never safe, but it is least dangerous in the cold hours before dawn during the pre-monsoon season, roughly April and May.

Cold ice is more stable ice. Once the sun hits the glacier, meltwater works into the cracks, and the structure loosens, which is why teams leave Base Camp between about 2 am and 4 am and aim to be through before mid-morning.

Season matters as much as time of day. Most expeditions run in spring because the weather window is more reliable and the glacier is still holding together after winter. By late May, the melting speeds up, the route becomes harder to maintain, and the Icefall Doctors eventually pull the ropes and ladders out.

Our best time to trek to Everest Base Camp guide covers how the same seasons affect trekkers on the trail below.

Khumbu Icefall FAQs

Seeing the Khumbu Icefall for yourself

You will not climb the Khumbu Icefall, but you can stand below it and watch a glacier come apart in slow motion. For most people, that is enough. It is the point on the trek where the difference between trekking to Everest and climbing it becomes obvious.

If you want to see it, the Everest Base Camp trek takes you there in around 12 to 14 days, with time at Base Camp and a sunrise on Kala Patthar. We have been running this route for years with our own guides from the Khumbu, some of whom have family working on the mountain above.