Stuntman Dies on Captain Jack's Tutorial: On August 6, 2009, a 47-year-old cast member named Mark Priest was playing the role of a pirate in the "Captain Jack's Pirate Tutorial" show when he slipped on a puddle on the stage and hit his head on a wall. Priest suffered a broken vertebra in his neck and severe lacerations on his head that required 55 stitches. He died August 10th due to complications from the head injury.
Seriously though I am surprised deaths don't happen more often. The Walt Disney parks had 132,549,000 visitors just in 2013. So just in that year alone the average was more than 37 thousand people per day.
I'll bet you it is statistically safer to play and have fun inside their parks than the trip flying or driving there.