I read this classic and it is a classic from the early teens of the internet.
Its well done for its type and executed with pictures.
Of course its not true and I can explain why - my idea is that this is a caver for sure (as he has some experience shown in his writing) and he has gone underground as that part is well conveyed.
Having done some small amount of caving myself I can absolutely attest to it being a very different experience to normal life and a place the imagination can work free.
The main reason I know this didnt happen is because of one of the pictures. We see a picture of Ted almost stuck in the small tunnel as he is squeezing through. In that picture he says quite sensibly that this was a picture not of that day but taken later - though it cant be. At NO POINT in his story was anyone else ever on the inside of the cave with any camera and nor were they running a rope beside him.
If this picture is of Ted going through a small crawl space to the larger "new" cave area then who took the photo ?
B was behind him
Joe who appears but briefly went through sure, but on his own and came back afraid. I don't see any point this photo could be taken.
I suspect they did go into an old granite and quartzite series of caves
I think they likely found a hole
They probably did open the hole up
They also found some caverns and explored them
All that I find believable and it explains the photos taken.
However its all too convenient the video was dropped, no photos came out of the larger room and the round rock (blocking the evil tunnel) was at the side of the cave it seems.
Still well written story and it didnt overplay things, just enough scare and we saw no monster to make it less believable. 9/10