Dog dies in overhead locker on United Airlines plane - BBC News
Whatever anyone here thinks about the rights and wrongs, it would appear this was a puppy in an approved container being transported according to the regulations of the carrier. The FA gave incorrect instructions to the passenger to place the carrier in the overhead locker. The passenger complied after protesting. The animal subsequently died in the locker. The airline has accepted full responsibility and stated the FA was in the wrong.
That seems pretty much done and dusted to me.
Whether American airlines should continue to emulate Noah's Ark is another subject..