If the death of a woman occurs it's because she was being reckless. People don't just die out of nowhere! They have to have done something super crazy to cause it. Right? Yes... right.
As you watch the news about this reckless woman you find out that she died from mowing (もう) her lawn. You're not sure how, but now you really believe that she had to be doing it really recklessly to die doing it.