Most cave dives are completed successfully. People who die are generally untrained and ill-equipped for an excursion they often make alone or with an equally untrained buddy, or they're very experienced people who either have become blase and careless, or they're pushing the envelope.

It is worrying when you hear of untrained and inexperienced people being taken into real caves, such as is quite often done in the Mexican Yucatan. But unless the news is suppressed (!) there are remarkably few problems.