In this May 18, 2013, photo, climbers make their way to the summit of Mount Everest.
Thirteen people died on Mount Everest early Friday after an avalanche swept down the route used to climb the world’s highest peak, NBC reported.
All of the dead and injured were believed to be Nepalese Sherpas working to prepare the route with equipment and ropes ahead of the main climbing season that begins later this month, The Economic Times reported. The ethnic Sherpas work as guides for foreigners who come to the mountain.
About 100 Sherpa guides and climbers are thought to be trapped above the avalanche site, according to The New Indian Express.
A climber who witnessed the avalanche told ABC News that the avalanche “came out of nowhere.”
“Without warning, a large chunk of ice broke loose,” Australian climber Gavin Turner told ABC News. “There were a few seconds of panic where I thought, ‘This is going to collect us.'”
The avalanche hit relatively low down on the mountain between base camp and camp two, at 21,000 feet. The peak of the mountain is 29,035 feet.
This infographic from Agence France Presse shows where the avalanche hit:
The area around where the avalanche hit is called “popcorn field.” Here’s what it looks like:
NBC News also spoke to witnesses on Mount Everest:
“To lose this number of people at the very beginning of the season may be the end of the season here,” said a cameraman who is on Everest working on a project for NBC and the Discovery Channel.
Soon after the avalanche hit at about 6:30 a.m., first responders and fellow climbers geared up to help. A helicopter was also dispatched from Kathmandu, the Associated Press reported.
‘‘Rescuers have already retrieved four bodies and they are now trying to pull out two more bodies that are buried under snow,’’ Ang Tshering Sherpa, president of the Nepal Mountaineering Association, told the Sydney Morning Herald.
The avalanche is the deadliest in eight years, according to Reuters.
The worst recorded disaster on Everest happened May 11, 1996, when eight climbers died after being caught in a blizzard close to the summit.
Nearly 250 people have died on Everest.