It is a general rule in Florida that the death of a party does not terminate a contract unless the contract was for personal services. Contracts for real estate are not personal services contract, so a death would not terminate the contract.
If the buyer to a real estate contract dies prior to closing, the contract remains valid. The rights to the contract will pass to the deceased buyer’s heirs. The buyer’s heirs will need to decide whether to purchase the property. If they decide not to purchase the property, then the Seller can make a claim against the buyer’s escrow deposit or pursue some other remedy for a default under the contract.