Sad news but bad headline

Oh I am sorry to hear bad news about an elderly lady died of carbon dioxide at a McDonald's. The following is from CNN:
I am sure lawsuits will result and lawyers will work hard. But the headline is wrong. CO₂ not CO². Chemistry demands subscript... It would be quite interesting if a headline nearby claims so American students fail science. I am never fond of chemistry... It's over my head. But I manage to pass my high school class.