Warm temperatures caused a partial collapse of the Seattle area’s popular Big Four Ice Caves on Monday, leaving one hiker dead, according to the Seattle Times.
The ice caves are located in the Mount Baker-Snoqualmie National Forest, 70 miles northeast of Seattle, and formed by avalanches off the nearby Big Four Mountain. Unusually warm weather increased the risk of cave collapses in recent months. “As we head into the busiest and warmest part of the season, the cave is in its most dangerous state,” Lead Field Ranger Matthew Riggen said in a Snohomish County press release in May. “The cave is in a condition that we would normally not see until at least September—large, inviting, and collapsing.”
The body of the deceased, who has not been identified, has not been recovered because of dangerous search-and-rescue conditions, the Seattle Times reports. The five injured—three adults and two children—were hospitalized, and one remains in intensive care.
The area will remain closed indefinitely.
Watch: This collapse at the Big Four Ice Caves happened the day before the collapse that killed one hiker and injured five others.