United Airlines flight 811

On Feb 24, 1989 a United Airlines Boeing 747 was suddenly shaken by a loud explosion followed by complete chaos. A giant hole had formed on the right side of the fuselage, & sadly several rows of seats were blown out of the cabin. 9 passengers lost their lives that day, but why? The NTSB first said it was human error, but 2 years later new evidence made them change their minds. What was that evidence? This is the story of the tragedy & subsequent investigation of United Airlines flight 811.