One person has died, two people remain trapped and one person was injured after an ice canyon wall collapsed during a group tour of a glacier in southeastern Iceland, authorities said.
Emergency responders received a call about 3 pm that a group of about 25 tourists with a tour guide were exploring ice caves and canyons on the glacier, Breidamerkurjokull, when the side of an ice canyon gave way, said Jón Þór Víglundsson, a spokesperson for ICE-SAR, a volunteer search-and-rescue association.
The glacier is part of Vatnajökull National Park, one of Europe's largest, spread across nearly 5,460 square miles.
Four people were hit by the falling ice, Lögreglan á Suðurlandi, the local police force, said on Facebook. Two of them were rescued, police said.
One victim was pronounced dead at the scene, and the other was airlifted to Landspitalinn, the National University Hospital of Iceland, and is in stable condition, the agency said on Facebook late Sunday evening.
Two people remain trapped, the agency said, and their conditions were unclear. A search-and-rescue effort that was underway to find the missing tourists was suspended late Sunday, authorities said.
"Conditions during the search are difficult and darkness is now upon us," the agency said, adding that it was dangerous to continue the search through the night. The search will resume in the morning, police said.
Others in the group remained uninjured, according to police.
It was unclear Sunday evening where the tourists were from, what tour company organized the expedition or how many guides were on the trip.
At least 150 people are involved in the search-and-rescue efforts, Víglundsson said. Crews have a "good feeling" on where the two trapped tourists might be, he said, but the operation is complicated.
"Although we think we know the location of the two missing, it is hard to say what amount of ice is between them and the rescuers," Víglundsson said. "It is a difficult situation."
Because of the precarious location on the glacier, teams cannot use heavy equipment and are instead using hacks, chain saws and ice picks to move the ice by hand to "clear a path" forward, Víglundsson said.
Crews are working in teams of 12 and in shifts, he said.
According to the U.S. Geological Survey, Breidamerkurjokull is an outlet glacier that extends from Vatnajökull, Iceland's largest glacier, into the Jökulsárlón glacial lagoon.
Breidamerkurjokull is famous for its ice caves. The best time to visit is in winter, according to Adventures.is, an Icelandic tour operator.
Vísir reported that tourism companies that have signed a contract with the national park are authorized to organize ice cave trips and glacier walks year-round, and that the park "trusts companies to assess the conditions."