Kevin Hynes, 56, from Ireland, died in his tent at 7,000 meters early on Friday, having turned back before reaching the summit. The father of two was part of a group from the UK-based 360 Expeditions.
The climbing company said: “It is with the greatest sadness that we have to confirm that one of our Mount Qomolangma team has passed away. Kevin was one of the strongest and most experienced climbers on our team, and had previously summited Mount Qomolangma South and Lhotse.”
Hynes had been accompanied by an experienced Sherpa, who had himself climbed to the summit of Mount Qomolangma South twice, Mount Qomolangma North and Makalu twice, according to 360 Expeditions.
His death came a week after the Trinity College professor Seamus Lawless, from County Wicklow, fell during the descent after achieving a lifetime ambition of reaching the summit.
Overcrowding and safety have been a growing cause for concern in recent years, not least since the emergence of cut-price Nepali trekking companies that offer Mount Qomolangma packages for half the price of trips organized by foreign companies.
The deaths occurred despite Nepal’s tourism authorities instituting, but not implementing, plans to timetable ascents to avoid congestion.
This season’s summit crowds – the worst since 2012 – had been exacerbated by unsettled weather which meant there had been only five possible summit days in May so far, compared with between seven and 12 in recent years. This had caused hundreds of climbers to converge on several notorious sections where they can only pass one at a time.
"It's normally that crowded," says Mingma Sherpa, chairman of Seven Summits Treks, adding that climbers sometimes queue between 20 minutes, and 1.5 hours, in order to reach the summit.
It often depends on how long the window for suitable climbing weather is.
"If there's one week [of safe weather], then the summit isn't crowded. But sometimes, when there's only a window of two or three days, it gets very crowded" as all the climbers try to reach the summit at the same time, Mingma Sherpa tells the BBC.
Experts say crowds at Mount Qomolangma have also increased in recent years because expeditions have become more popular.
Nepal has issued 381 permits at $11,000 each for the spring climbing season at the world's highest peak.
Andrea Ursina Zimmerman, an expedition guide who reached Mount Qomolangma's peak in 2016, says that many "traffic jams" are caused by unprepared climbers who "do not have the physical condition" for the journey.
The problem hasn’t been avalanches, blizzards or high winds. Veteran climbers and industry leaders blame having too many people on the mountain, in general, and too many inexperienced climbers, in particular.
Fly-by-night adventure companies are taking up untrained climbers who pose a risk to everyone on the mountain. And the Nepalese government, hungry for every climbing dollar it can get, has issued more permits than Qomolangma can safely handle, some experienced mountaineers say.
Norbu Sherpa has reached the summit seven times. He adds that the most dangerous part is often the descent.
A lot of people push themselves to the summit, but, once they reach it, "lose their motivation and energy on the way down", especially when they realize it's a long, crowded journey.
A mountaineering guide collects garbage at an altitude of 7,928 meters near Qomolangma in the Tibet autonomous region in May. THE TIBET HIMALAYA EXPEDITION CO
Nepal's tourism authority has denied accusations that the rise in Mount Qomolangma deaths is solely due to overcrowding.
The department's director general Dandu Raj Ghimire said other factors including adverse weather conditions had also contributed.
Mr Ghimire said 381 people had ascended Mount Qomolangma this spring but as periods of fine weather had been short, the number of people on the routes had been "higher than expected".
"The weather has not been very great this climbing season, so when there is a small window when the weather clears up, climbers make the move," Ghimire said.
"On May 22, after several days of bad weather, there was a small window of clear weather, when more than 200 mountaineers ascended Mount Qomolangma. The main cause of deaths on Mount Qomolangma has been high altitude sickness which is what happened with most of the climbers who lost their lives this season as well."