Underwater Gothic: here's a sad, compelling account of divers perishing in a deep, deep pit. It's a scary account, too, due to a clutch of fears: fear of drowning, claustrophobia, dead and warped bodies, exhaustion, mental disorientation.
Some of the horror is quiet, understated, like this:
The team had been doing a practice dive. On the way back up, at 196 feet, Deon appeared to be fine, exchanging hand signals with his buddy. The group continued ascending. At 164 feet they suddenly noticed a light below them. A quick, confused diver count came up one short. Team leader Dietloff Giliomee wasn't sure what was happening. Then another diver, in the eerie glow of his submersible light, dragged his finger across his throat. Giliomee desperately started swimming down but stopped when he realized the light below him was already more than 100 feet deeper and fading fast.
There's also a fearsome media angle, as the tale concludes with the description of a videotaped death: