The JAL accident IIRC was caused because the boeing engineers who repaired the aft pressure bulkhead used only one line of rivets instead of two & the pressurisation cycles led to stress cracking & eventual explosive decompression which ruptured all the hydraulic systems thus crippling the crews ability to fly the airplane.
Worst of all, the plane flew on for a while & in the wreckage, the rescuers found all kinds of final notes for loved ones that the pax had time to write in the certain knowledge they were about to die. A horrible crash that one.