If a anvil drops on redstone, if above 2 or more blocks, the redstone gets destroyed, and deleted.

Video: https://www.youtube.com/watch?v=ZfqU3TnG8OY

Also happens to: "Redstone Torch", "Comparator", "Repeater", "Button[Wood]", "Button[Stone]", "Lever", "Tripwire[Hook]", "Tripwire[String]", Not redstone related: "Torch", "Peony[2HI]", and the list goes on.

To recreate:
1. Put down redstone
2. (if didn't already) Build up 3 block behind redstone dust
3. Drop anvil from two blocks above redstone
4. Search for the redstone, then go "Where is that redstone!?"