I tend to stay out of these discussions, but only fully trained cave divers should be attempting any diving inside a cave. SEALS (US or otherwise) are highly trained, but not for this type of diving. It is literally the most dangerous type of diving possible, and probably the most dangerous "sport" out there. Mistakes are generally fatal. Almost every cave in the US that you dive in has a "STOP YOU WILL DIE" placard at the entrance. It is a standard thing.

I was (am) fully cave trained, but I am way out of practice which is also necessary to maintain proficiency. I feel for the families (trapped and rescuers) as this is a really bad place for everyone. Looking at the video feeds and the equipment set-ups, there will unfortunately be in all probability more fatalities.