I am so sorry for your loss.  You are going to have to do a little snooping around.  Generally speaking, people usually have keys to boxes in the banks in which they do their banking.  The box number is usually witten some where in the bank records as linked to their account. Once a personal reppresentative is appointed he or she can inquire as to if there is a box at local banks- those near to his home are a good place to start - and by sending a letter to the banks.  Good luck.