Forty years ago, a mountain climber from Germany went missing while climbing in the vicinity of the Matterhorn. Precisely what happened to him has been a mystery in the decades that followed — until earlier this month. As The Guardian reports, two climbers were making their way along the Theodul Glacier, located near the Swiss mountain in question, when they saw something unexpected in a thawing patch of ice.

The climbers’ discovery included human remains as well as some items that one would expect to find on someone making their way through the mountains, including a crampon and a boot. They notified the authorities, who began the process of investigating; eventually, a DNA test confirmed that these remains belonged to the missing climber.

As The Guardian‘s reporting points out, this discovery is a result of two linked phenomena. Unfortunately, not every climber who sets out to climb the Matterhorn — or any mountain — makes it back from the process. And with climate change raising global temperatures, remains that had previously been situated in ice have thawed. This isn’t the first time that long-buried human remains have been discovered on or near the Matterhorn in recent years.