About 30 years ago I became trapped in an alpine cave in a way very similar to Floyd Collins, when a football sized piece of marble fell from the ceiling about 30 feet into a virgin body sized phreatic tube I was exploring.
It landed on my ankle, pinning it so I couldn't move forward or back, and the passage was so tight that I couldn't move my free leg to dislodge it, and yes, Floyd Collins entrapment was the first thing I thought of.
Thankfully, I had two things in my favor, one was I had a caving partner on the surface who knew where I was, and I could communicate with, so if I couldn't self rescue she could hike the 5 miles back to a road end and get help (no cell phone service back then).
And two, I was an experienced caver, so I remained very calm, and kept working my free foot in order to attempt to dislodge the rock pinning my ankle, and after about 10 minutes I was able to somehow with great effort, shift the rock enough that I could move deeper into the cave.
I crawled forward another 15 feet to a pit about 20 feet deep that I was able to free climb into so I could turn around and head back out, and was able to push the rock ahead of me and I got out just fine.
It didn't phase me one bit, as I'd had much more serious life threatening events in caves previously (almost "flat rocked" in Lechuguilla Cave, NM), but I was well aware that it could have been a serious situation as it got down into the 20's at night in that location, so hypothermia was a real possibility.
The lesson here for non cavers is, don't explore caves alone, especially if nobody knows where you are, and get proper training before doing so, from a local "grotto" (chapter) of the National Speleological Society https://caves.org/ .