I haven't ever really felt unsafe at the parks either from ride malfunctions or incidents involving other guests. Disney can't afford bad PR like that, as bad as it sounds saying reputation is the most important thing (and not the loss of life), but I'm sure they do everything they can to maintain the integrity of their attractions. However, humans are not perfect and, at times, forget to do things or are told to cut back on certain procedures to save time and money. No matter what the reason,
Disneyland has always been quite safe if you're not counting the people who injured or killed themselves of their own ignorance.