On the 26th of April, 2003, then-26-year-old climbing enthusiast Aron Ralston was involved in an accident in the Blue John Canyon in south-eastern Utah. While climbing down a slot canyon, a boulder that he was using to support his weight became dislodged and pinned his right hand against the canyon wall. On this particular occasion, Ralston had not told anyone in advance that he was going on a climbing trip, and as such, he knew that it was unlikely anyone would come searching for him.
Over the proceeding days, Ralston rationed his 350ml of water, and 2 burritos, and was eventually forced to drink his own urine. During the course of the event, Ralston created a video diary for his friends and family, with the assumption that he was going to die. After three days of trying to chip away at the boulder with a knife, Ralston decided that he would attempt to amputate his forearm. He was successful in cutting into the flesh, but the knife was no match for the bone, and he eventually gave up on the amputation idea. On the fifth day, Ralston carved his name and predicted date of death into the wall, and recorded his last goodbyes to his family. He didn't expect to make it through the night.
Upon waking at dawn the next day, Ralston has an epiphany that he could break the bones in his arm using the torque against it. He did so, and then completed the amputation over the course of an hour, using a tourniquet to stop the blood flow, and having to cut through muscle tissue, and even a nerve (which he reported to be extremely painful) with his multitool (namely pliers and a dull, 2 inch knife).
After freeing himself, Ralston exited the canyon and repelled down a sheer wall with one hand, before attempting to hike 13 kilometers to where he had left his car. Fortunately, on his way he encountered a family on vacation from the Netherlands, who gave him food and water and alerted the authorities. Ralston feared that he would bleed out before authorities arrived, but, miraculously, moments later a helicopter search party (that was specifically looking for Ralston, after his family reported him missing) passed overhead, saw him, and picked him up, 6 hours after he had completed the amputation.
In 2010, a movie titled 127 Hours (the amount of time that Ralston spent trapped in the canyon) was released starring James Franco. To prepare for the role, Franco and the film's producers were allowed to view the home video footage that Ralston had recorded, and the transcript for the film (at least the scenes where Franco is recording himself) were taken verbatim from Ralston's own video. Ralston was asked in an interview if he would ever make his footage public, and while he understood the intrigue and interest behind the concept, he politely declined, stating that it was a private, personal video made for his family and friends (many of whom have seen it), and that he intended for it to remain that way. Despite this, one video clip has been released, as well as a compilation of audio snippets, taken from different sections of the tape.