No one knows what would happen. That is unprecedented. There would be mayhem in financial systems as all types of collateral is vaporized. All types of on paper net worth would collapse towards zero
I am not saying it would be pretty or desirable, but by reading what happened to countries can give a notion.
It would eliminate the notion of the USD as the basis of foreign trade across the world, almost all of the finance system is supported by the USD being the safest investment available.