https://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243
edit: Earlier door failures happened to two McDonnell Douglas DC-10-10 after they changed their locking mechanism
https://en.wikipedia.org/wiki/American_Airlines_Flight_96
https://en.wikipedia.org/wiki/Turkish_Airlines_Flight_981
Situation back then was made worse as it sucked part of the floor out with the door.