| Clue | Source | Date |
|---|---|---|
| Sudden collapses | LA Times Daily | 25 Mar 2023 |
| Serious concerns for spelunkers | Universal | 07 Dec 2022 |
| Structural collapses | USA Today | 29 Oct 2021 |
| Perils for spelunkers | ||
| Miner concerns | ||
| Utter capitulations | ||
| Mine disasters | ||
| Spelunker's concerns |