If a Will is lost or can’t be found, the specific facts and circumstances and state law will determine what happens.
For instance, if the Will is missing because the decedent intentionally revoked it, an earlier Will or the laws on intestate succession would determine who gets the decedent's estate.
Or, if a Will is missing because it was stored in a bank vault destroyed in a fire, the probate court may accept a photocopy of the Will (or the lawyer's draft or computer file), if there is evidence that the decedent properly signed the original.