Tourist Cave diver here, kicking up a little dirt happens on almost every dive, we train to deal with complete blackout scenarios, while sharing air, in restrictions but that rarely happens. Typical incidents relate to people doing a dive over their experience level or getting lost and running out of gas. Some cave systems are truly huge in scale and navigation can be difficult if you do a huge dive in one go. Personally i will only make 1 new navigation decision per dive so i can always visualize the cave. This goes out the window for those doing exploration type dives, then anything can happen.