Hundreds of climbers hoping to make it to the summit of the world’s tallest mountain were forced to queue for hours in freezing temperatures at high altitude this week as congestion built up on Mount Everest.

The delays have been linked to the deaths of at least three people on the mountain, according to local media. An American man and an Indian man and a woman all died as they descended, various sources said.

Donald Lynn Cash, 54 and from Utah, collapsed while taking photographs at the summit and died as he was being taken down the mountain by Sherpas, according to Pioneer Adventure, his expedition’s organiser.

Cash, who leaves a wife and four children, died “accomplishing his dream of summiting the seven summits,” his daughter Danielle Cook posted on Facebook on Wednesday, referring to the challenge of climbing the highest peaks on all seven continents.

Anjali Kulkarni and Kalpana Das died in similar circumstances in separate incidents, said the Kathmandu Post. The paper reported on Thursday that the deaths of all three had been linked to the lengthy queues above 8,000 metres (26,200 ft) – known as the Death Zone.

A spell of good weather prompted many of those granted permission to climb this year to go for the summit at the same time, it said. It noted previous warnings about a rush to the top if lengthy periods of poor weather were punctuated with good days.

“This is a huge problem because the route is already dangerous, and there is always risk. And a lot of traffic makes the journey quite difficult,” Pioneer Adventure’s manager, Nivesh Karki, told the New York Times.

Kulkarni, 54, died while still in the Death Zone, according to Thupden Sherpa, the general manager of her expedition’s agency. He told the Kathmandu Post she died of exhaustion after she and her husband were “forced to wait for hours to reach the summit”.

The Himalayan Times quoted a local government official, Meera Acharya, as saying Das – who also reached the summit – had died while descending the mountain.

Cash’s daughter told NBC’s Today Show that a cause of death has not been officially determined but family members believe he suffered a heart attack.

Before he headed for the summit, Cash texted his son Tanner to say that he felt “so blessed to be on the mountain that I read about for the last 40 years”.

Cash said on his LinkedIn page that he left his job as a sales executive to try to join the so-called seven summits club of people who have climbed the highest mountains on each continent. In January, he wrote, he climbed Mount Vinson Masif, Antarctica’s tallest peak.

Friend and former colleague Josh Ray said Cash was “larger than life, everyone loved him, and he always left you with a smile”.

An Irish professor, Seamus Lawless, died on Everest last week after falling during his descent from the peak.