<P> On April 26, 2003, Aron Ralston was hiking alone through Blue John Canyon, in eastern Wayne County, Utah, just south of the Horseshoe Canyon unit of Canyonlands National Park . While he was descending a slot canyon, a suspended boulder became dislodged while he was climbing down from it . The rock smashed his left hand, and then crushed his right hand against the canyon wall . Ralston had not informed anyone of his hiking plans, nor did he have any way to call for help . </P> <P> Assuming that he would die without intervention, he spent five days slowly sipping his small amount of remaining water, approximately 350 ml (12 imp fl oz), and slowly eating his small amount of food, two burritos, while trying to free his arm . He wasn't able to free his arm from the 800 lb (360 kg) chockstone . After three days of trying to lift and break the boulder, the dehydrated and delirious Ralston prepared to amputate his trapped right arm at a point on the mid-forearm in order to escape . After having experimented with tourniquets and having made exploratory superficial cuts to his forearm, he realized, on the fourth day, that in order to free his arm he would have to cut through the bones in it, but the tools available to him were insufficient to do so . </P> <P> After running out of food and water on the fifth day, Ralston decided to drink his own urine . He carved his name, date of birth and presumed date of death into the sandstone canyon wall, and videotaped his last goodbyes to his family . He did not expect to survive the night . After waking at dawn the following day he had an epiphany that he could break his radius and ulna bones using torque against his trapped arm . He did so, then amputated his forearm in about one hour, with his multi-tool, which included a dull two - inch knife . The manufacturer of the tool was never named, but Ralston said "it was not a Leatherman but what you'd get if you bought a $15 flashlight and got a free multi use tool ." </P> <P> After freeing himself Ralston climbed out of the slot canyon in which he had been trapped, rappelled down a 65 - foot (20 m) sheer wall, then hiked out of the canyon . He was 8 miles (13 km) from his vehicle, and had no phone . However, while hiking out of the canyon, he encountered a family on vacation from the Netherlands, Eric and Monique Meijer and their son Andy, who gave him food and water and hurried to alert the authorities . Ralston had feared he would bleed to death; he had lost 40 pounds (18 kg), including 25% of his blood volume . Rescuers searching for Ralston, alerted by his family that he was missing, had narrowed the search down to Canyonlands and flew by in their helicopter . He was rescued four hours after amputating his arm . </P>

How does he cut his arm off in 127 hours