The original documentary of the 1988 Pannikin Plains Expedition, Nullarbor Dreaming, is now available on YouTube:
A team of international cave divers set out on an amazing adventure to explore the mysterious subterranean waters of Pannikin Plains Cave on the Nullarbor Plain in Western Australia. Their epic underwater exploration nearly ends in tragedy when a rare cyclonic storm hit the area and a deluge of rain results in a flash flood that funnels water into the cave causing the entrance to collapse blocking the main route out of the cave. Fifteen team members are trapped below ground. This documentary is a graphic account of the expedition and their escape.
In the excerpt below from an Australian Geographic podcast, Ron Allum gives some insights into the 1988 Pannikin Plains Cave expedition where a massive storm with torrential rain and flooding caused tons of boulders and dirt to collapse in the cave entrance trapping the crew of divers underground: