Mickey Wilson set out to have fun skiing on a Colorado mountain. But he wound up saving a man’s life.

Wednesday night, Wilson used social media to report on his story of rescuing a friend. The images and video were published on Facebook and Instagram. They have been shared thousands of times in the past 24 hours.

Wilson said his friend became caught on a chairlift. Chairlifts carry people from the bottom of a mountain to its top so they can ski down the hill.

Wilson’s friend was wearing a backpack. When it was time for him to get off the chairlift, the backpack became caught and he could not get off. The lift circled around and started bringing him back down the mountain.

The man was hanging from the chairlift, with the bag wrapped around his throat. Wilson said his friend was not able to breathe.

Other skiers gathered under the man’s chair and tried to think of a way to reach him. But they could not get him down.

Wilson had an idea. He climbed up a tall, nearby structure and then climbed across the lift’s guide wire to reach his friend. He used a knife to cut the backpack strap that was caught.

His friend fell a little over three meters into the snow, where rescue workers helped revive him. They brought him down the mountain and took him to a hospital.

Wilson told a Denver newspaper it was one of the most frightening things he had ever seen.

Wilson said he was confident he could help his friend because of his experience as a competitive slackliner.

Slacklining is an acrobatic activity where a person balances and does tricks on a narrow strap tied down at both ends.