to that point I'd never had a problem.

We got to the entrance and I dropped into the hole with some friends. I took a look at the crawl space to get inside and froze. After some time and reassurances from friends that it opened up once inside I went in. For most of the exploration I was okay knowing what was behind me, always having a way to move to the exit if needed, and feeling cool air which at least gave me the thought that I was getting fresh air.

Once we got to the spot that people called the birth canal I was having none of it. My group of friends went on while I waited. I am sure the other side was incredible but I just could not bring myself to shimmy through that hole, particularly if anybody was behind me. None of my group got stuck or had any problems.

A few months later another group of friends from my high school went down there. One of them did get stuck and had to be rescued. Then, as the OP mentioned, a couple years later there was a death in that crawl space.

I've been well aware of my claustrophobia ever since.