if you can run an air line with access every few feet - which would mean inline regulators every few feet.. I dunno if that exists or is possible.. you'd think by now it should be, but if it does exist, I dunno about it.. Yeah, a seal before and after every kid - you really need one HOLDING each kid.. then stick to the line tied to the entrance and pull yourself out.. Only issue sI know about are there is zero visibility in the majority of the flooded areas, which makes things tough, but still totally doable with a safety line tied.. we've been in haloclines so bad in caves that there was zero visibility - you suck it up and stick to the line..
Like I said in another post, tho, I don't know the depth of the water nor the length they have to go underwater.. You still run into issues like kids holding their breath as they ascend blowing out a lung or sustaining an embolism.. might be tough to keep a kid breathing, as he ascends, in zero visibility.. There are some factors that could make it much harder - I just don't know all the facts, yet.. then again, they could be sensationalizing this a bit - the media has been known to do that from time to time..
Friendship is like peeing your pants.. Everybody can see it, but only you can feel the warmth..