I am always of two minds about looting during natural disasters.
On the one hand theft is wrong, and stealing from persons absent who are suffering from a disaster is, moreover, low and cowardly in a way that, for instance, armed robbery or even embezzlement is not.
On the other hand, if the inventory taken was about to be destroyed or (declared a total loss by an insurer, even if not destroyed), whether directly by flood waters, or indirectly through lack of refrigeration, the owner is no worse off if it is, instead, taken by someone who can use it. I think one can make a case that our Founding Fathers might have recognized as valid, on the basis of Lockean property theory, that the appropriation of goods which have been rendered useless to their owner is not, in fact, theft, but appropriation from common.