An American man was killed and an American woman was injured in Iceland after the Breitamärkurjokull ice cave collapsed, Icelandic Broadcasting Corporation (RUV) reported on Monday.

The rescue operation that began on Sunday evening has now ended, with police announcing that there are no more people trapped under the snow, according to the public broadcaster.

A group of 25 tourists from several countries were exploring an ice cave in the Bredaamkurjokull glacier in southeast Iceland when the accident happened shortly before 3 p.m. on Sunday, local police said. Four people were injured by falling ice.

The American couple were rescued on Sunday, but the man was pronounced dead at the scene, while the woman suffered injuries of unknown severity and was taken to a hospital in Reykjavik, RUV reported.

More than 200 responders were involved in the operation, RUV reported, citing police, and a massive amount of ice was broken up and moved, almost all by hand. CNN has reached out to police for details.

A US State Department spokesman confirmed that one American citizen was killed and another was injured, saying they were “ready to provide consular assistance.”

“We offer our deepest condolences to the family and loved ones on their loss,” the spokesman said.

The spokesman did not provide details about the circumstances of the deaths or injuries or information about the identity of either of them. The State Department does not typically provide personal information about Americans killed or wounded abroad.

Ice caves are a popular destination for visitors to Iceland, with tour operators offering customers the chance to “explore inside the glaciers” and see the blue color and “amazing patterns” in the ice, according to the Associated Press.

Glaciers cover about 11 percent of Iceland, an island nation in the North Atlantic Ocean on the southern edge of the Arctic Circle, according to the Associated Press. The largest is Vatnajökull, which covers 7,900 square kilometers (3,050 square miles). Bredamarkurjökull is the tongue of Vatnajökull that ends at Jökulsárlón Lake, where icebergs constantly break off the glacier.

According to the U.S. Geological Survey, the Breiðamerkurjökull River continued to grow until the early 19th century, but since about 1930 it has been melting due to fossil fuel pollution that is warming the planet.

The local news site Viser said the group in the cave when it collapsed was on an organized guided tour. The Associated Press reported that most of the people were outside the cave when it collapsed.

Transporting rescue equipment and rescue personnel to the glacier was difficult due to the rugged terrain, and rescuers had to use electric saws to cut through the ice, according to the Associated Press.

The glacier is located about 300 kilometres (185 miles) from The volcano that erupted on Friday On the Reykjanes Peninsula in southwest Iceland.

Iceland has been affected by human-caused climate change and is warming about three times faster than the rest of the planet, according to the Icelandic Meteorological Office.

Report contributed by CNN’s Jennifer Hansler and Angela Fritz.