There have been fires and worse, master tapes thrown in landfills because they were taking up space that could make more money another way.
I hang out on some archivist forums/mailing lists and I remember when the Universal fire happened.
There were lots of questions about what was stored there and just a few hints about stuff like the Chess tapes.
UMG did a great job of covering up the whole thing by starting rumors that the claims of priceless masters were folks trying to spin a big story out of a minor one.
It wasn't until this NYT story was released that the true depth of the tragedy was beginning to be reveal to the general public.
Thankfully, other labels haven't been so careless and take their stewardship seriously.
A lot of these disasters have been allowed to happen because of the endless shuffling of record labels and copyrights ownership.