A lot of Liability here, that you have left or are leaving and did not secure the the contents.. Important!!! the ALARM to the building and Vault Door must be kept on....First you will have to look at your state laws.. Many States have a law that requires 30 day notification by certified mail of a branch closing and that the safe deposit boxes are or are not not being relocated..
1. Key and Contract Audit ( every box should have either a key or a contract)
2. Under dual control inspect every bond tin to insure that ALL are empty ( Many times I have still found contents when the bank said the boxes were empty.. the worst case I found at a bank warehouse 17 boxes still with contents.)
3. After Proper customer notification drill the remaining rented boxes under dual control plus a notary, inventory the contents. Also at this time Drill open all mystery boxes. (no keys or contract found)
4. Transfer the contents to the either the nearest location or main location and place in safe keeping along with all the records including the return receipts to prove that you attempted to notify. Eventually you will escheat the contents to in accordance with PA state law.
once again check with PA. state laws and procedures regarding branch closing, box drilling and relocation of safe deposit boxes and contents.
Finally keep your fingers crossed and pray.
Best of Luck.. Charlie