People really like killer whales — from the popularity of whale watching and movies like “Free Willy,” to the recent viral tale of a killer whale carrying its dead calf for over two weeks off the coast of Vancouver, British Columbia.

That makes the possible population collapse of these iconic creatures even more distressing.

A paper in the Sept. 28 issue of Science says killer whales are at great risk, but not from climate change, loss of habitat or loss of their prey. It will be due