On August 12 1985, Japan Airlines flight 123 took off from Tokyo, headed for Osaka. Twelve minutes into the flight, at 23,900 feet, part of the plane ruptured, damaging the plane's tail and destroying the hydraulic system. The pilots, despite being unable to steer the plane, kept it in the air for more than 30 minutes, before it crashed on Mount Otusaka.
Incredibly, 4 people survived the crash, one of whom was a 12 year old girl found in a tree. The death toll of 520 made it the worst single-plane accident in history (the Tenerife crash involved two planes). The rupture was blamed on an incorrect repair made to the plane seven years earlier.