#1 Owen Hart's death
No event in WWE history changed WWE quite like the death of Owen Hart. It was a horrific and heart-wrenching incidence and all the more shocking due to its circumstances. Hart didn't die of in-ring injuries or botched moves but of something as simple as an entrance stunt gone wrong.
At WWE pay-per-view event Over The Edge, Hart was scheduled to ascend into the ring with the help of a harness. The stunt, unfortunately, went terribly wrong and Hart sustained injuries that cost him his life.
The untimely demise of a wrestler as incredibly talented and gifted as Owen left a void within the company and one has to wonder how far this star would have risen if not for this tragedy.
Even in his short career span, Hart left behind an enviable wrestling legacy that continues to inspire and motivate the upcoming superstars.
While this was a disastrous incidence, the one upshot to it was that WWE upgraded their safety protocols after it and the well being of the company was given higher credence than ever before.