We visited the Grand Canyon Caverns last week. After a 1-hour tour, I was more than happy to get into the elevator and head back up. They actually have a HOTEL ROOM down there. For $700, you get to spend the night in the cavern, and it includes dinner and breakfast. Plus, it covers the cost of a paid attendant who stays at the top, but will come down and bring you out if the claustrophobia gets to you in the middle of the night.
I "MIGHT" make it through dinner. I can't imagine the 2 months those miners have been trapped underground.