The twenty-six-year-old went hiking alone in Canyon Lands National Park in the western state of Utah. A huge rock became loose and sent him falling into a deep crack in the canyon. His right arm was crushed between the rock and canyon wall. Aron Ralston could not move. He knew his chances of survival were low because he had not told anyone where he was hiking.

Aron Ralston spent one hundred twenty-seven hours trapped and alone. Finally, after five days, he decided he had to cut off his arm in order to escape. The young climber carried out the amputation using a small, unsharpened knife. Then he dragged himself from his rocky prison and hiked out to safety. Aron Ralston wrote a book about his experience called "Between a Rock and a Hard Place."