Mountaineer Aron Ralston in May 2003 was climbing in a Utah canyon when a boulder shifted and crushed his arm against a cliff. After spending several days in the remote canyon, pinned against the rock, he had tried everything to free his arm and had run out of water. So, on the fifth day, Ralston began doing what he had been thinking about all along: amputating his trapped arm.
He applied a makeshift tourniquet and he used a utility knife to rip and cut through his arm to get free. Then, he rappelled more than 60 feet down and hiked about six miles to his rescue.
Years later, Ralston leads an active life, though he now relies on a prosthetic limb.