Japan Airlines Flight 123 Crashes into Mt. Osutaka 

Japan Airlines Flight 123 was a Japan Airlines domestic flight from Tokyo International Airport (Haneda) to Osaka International Airport (Itami). The Boeing 747-SR46 that made this route, registered JA8119, suffered mechanical failures 12 minutes into flight and 32 minutes later crashed into two ridges of Mount Takamagahara in Ueno, Gunma Prefecture, 100 kilometers from Tokyo, on Monday 12 August 1985. The crash site was on Osutaka Ridge (おすたかのおね Osutaka-no-One?), near Mount Osutaka. All 15 crew members and 505 out of 509 passengers died, resulting in a total of 520 deaths and 4 survivors.
It remains the deadliest single-aircraft accident in history.