If there is wood...
I take issue with the idea that we will keep sliding back to the stone age. People are still inventing things right now, so it would take a lot of doing for a society sent backwards to keep going that way. Metal tools can be recycled. Scrap metal will abound. Skills can be rediscovered. People will experiment with things they heard about and try it. Some keepers of old knowledge may survive, and share as trade, or for power. Some societies may even escape destruction.