i wrote about this at some length in "sylvia porter's your finances in the 1990s," which you might want to take a look at, if one of the seven copies that sold happens to be in your local library. rule number one: put
nothing crucial in a safe-deposit box, because it will take a court order to get that box opened, which will take a longer time than the bereaved would want, particularly if it's the will and, say, life insurance policies.
dep
I've never understood the safe deposit box thing. For what you would pay over the life of the time you rent one, you could get a nice fire proof safe and install it in your house.