Jim is about correct. We did use Jenny for training. There is a pretty good sized room about 100 feet in, and a short circuit. You could dive the whole place on a single reel. There was never a permanent line in there that I remember. If you went in to the right side, the whole damn place got low, and turned to white clay after about 400 feet in. That is what happened to most of the people that died in there, they went in with no line, bad lights, weren't certified, and had a major siltout.
Doug Clark and I pulled a PADI instructor out, he had no line, a 3 cell flashlight, on a single 80. Doug and I were getting ready to dive when a diver surfaced screaming for his buddy. He was wearing double 72's and they were flat empty. He told us his buddy had a single 80. I remember telling Doug that we should hurry up, Doug said "there's no hurry". There wasn't.
Most of the stories, including the 4 students, are about the same.

