A man died while hiking with friends in the White Mountains of New Hampshire last week, despite grueling efforts by emergency responders to save him, according to a news release from the state’s fish and game department.

At around 4:30 P.M. on Friday, August 11, Jason Apreku, 21, suddenly collapsed on the Osgood Trail, which takes visitors up 5,367-foot Mt. Madison. His friends called 911 and began administering CPR while the National Guard was en route. Androscoggin Valley search and rescue team members also began ascending the peak “as a backup plan, in case the helicopter could not pick Apreku up off the mountain ridge,” the release says.

As part of the Presidential Range, Mt. Madison is among New Hampshire’s highest peaks, where weather conditions are notoriously unforgiving year-round. A weather station on nearby Mt. Washington recorded wind gusts of 90 miles per hour on the day that Apreku died, and the strong breeze dropped temperatures to below freezing. Due to high winds and low visibility, the National Guard helicopter was unable to reach Apreku, according to officials.

“After multiple hours of CPR, AED deployment, and many other life-saving efforts, Apreku succumbed to the unknown medical issue,” the release says.

Into the next morning, Androscoggin Valley search and rescue members, volunteers from the Appalachian Mountain Club, and conservation officers traveled on foot to Apreku’s location. The team brought his body over the summit of Mt. Madison and into the Madison Spring Hut. Two additional waves of rescue crews assisted in bringing Apreku off the mountain.

Authorities did not share information on the condition of Apreku’s fellow hikers. His cause of death has not been released.