WELLINGTON, New Zealand (AP) – Two Australian brothers have been crushed to death under a sheet of ice at a popular tourist spot during a family vacation in New Zealand, police said Friday.

The pair were struck and buried when a section of ice sloughed off the main face of South Island’s Fox Glacier late Thursday afternoon, said Constable Tony LeSueur.

The body of one of the men has been recovered, but rescuers have not been able to reach the second one, despite the use of a mechanical digger, because some of the ice blocks under which he was buried were the size of large vehicles, LeSueur said.

“It was too dangerous to carry on,” he said, adding that rescuers would consider whether to resume the operation later Friday.

The second brother is presumed to be dead, LeSueur said.

The brothers in their 20s were visiting New Zealand with their parents and extended family, he said. Their names have yet to be released by police.

Department of Conservation area manager Jo Macpherson said Thursday that the face was very steep and subject to random ice collapses.

The men apparently had ignored rope barriers set up to prevent hikers from wandering into dangerous areas.

Chief executive Rob Jewell of Fox Glacier Guiding, a private company that takes tourists around the glacier, told National Radio they had gone to the glacier without guides.

In 2007, the department said almost one in three of the 600,000 visitors to the region’s two glaciers ignored warning signs and entered danger zones.