By Kathleen Moody, Associated Press

Officials rescued a Colorado teenager Thursday after he fell into an old mine shaft that his friends said he was trying to explore.

Karlyn Tilley, a spokeswoman for the city of Golden Fire Department, said the 15-year-old injured his leg but wasn’t otherwise seriously hurt. Video showed rescuers using a system of ropes and pulleys to lift a stretcher holding the teen out of the mine shaft.

Tilley said rescuers found him about 100 feet inside the narrow, jagged mine shaft. It took rescuers about two hours to retrieve the teen, whose name has not been released.

Friends who were with him when he fell told rescuers that a rope snapped while he was trying to explore the mine shaft.

Tilley said the teen was using a nylon rope that wasn’t safe for any type of climbing or spelunking and didn’t have a helmet or other safety gear. She urged people to use proper equipment and wear protective gear when climbing.

She also urged anyone who finds a collapsed mine shaft to stay away.

“Collapsed mine shafts are extremely dangerous, and no one should attempt to enter them,” she said. “Instead, we ask people to report them to authorities.”

Tilley said rescuers believe the mine shaft had collapsed recently. It is southeast of the city of Golden, close to a hiking trail.