DW bought some fish at the local market that had been frozen but thawed due to a failed large commercial freezer (store ad implied that is why it was thawed vs. sold still frozen) .

Yuk, did that stuff smell like ammonia, told her 'that is why the freezer failed, NH3 leak"

Did not know it would permeate the fish so badly - any similar stories anyone has seen of refrigeration failures contaminating frozen food and it still be sold? No harm, but sure was unappetizing fish with the NH3 smell.