So sorry for your family's loss. What a terrible ordeal.
Your father in law can derive perhaps some consolation from the fact that his guns would almost certainly have been a total loss even if they were in the safe. Temperatures that won't destroy the safe can still destroy the items inside. Talk to a firefighter sometime about how many guns are removed from a safe that "survived" a fire only to have the guns inside be a total loss.
From what I understand, it's so common it's the rule, not the exception.
So your father in law need not beat himself up. He did nothing wrong, and his guns almost certainly couldn't have been saved.
Your father in law can derive perhaps some consolation from the fact that his guns would almost certainly have been a total loss even if they were in the safe. Temperatures that won't destroy the safe can still destroy the items inside. Talk to a firefighter sometime about how many guns are removed from a safe that "survived" a fire only to have the guns inside be a total loss.
From what I understand, it's so common it's the rule, not the exception.
So your father in law need not beat himself up. He did nothing wrong, and his guns almost certainly couldn't have been saved.