Storytelling is about getting the reader to understand a point or about getting the reader to feel an emotion (sometimes both). This is why writers tend to be drawn towards the extremes of human experience when writing narratives. It's much easier to get a visceral response in the midst of a shoot-out then it is in a polite discussion between parents about their children (not that it can't and hasn't been done).
The problem with writers' proclivity to go towards the narrative extremes is that their ability to write extreme emotions must come through. In other words, without identifiable human reactions to go along with extreme (plot) situations, the narrative will become melodrama, or worse, feel false to the reader.
Comic books are probably the best example for this. Since comic books are known for both their death scenes and coming back to life, a character's death (like Jean Grey's rather famous demise in Uncanny X-Men #136 over there) must mean something. In Jean's case, she sacrificed her own life to save the universe from her own growing powers. Her death then affected the rest of the cast and the stories told for the next ten years.
But recently, death has become something a breezy issue in comic books. Bucky's (Captain America's WWII partner) death in an event comic wasn't even dealt with, and the character didn't even die that heroically or surprisingly. Fans were upset. In other words, the plotting and the story didn't serve for Bucky's death to make sense to the reader.
Does death make sense to anyone in real life? No.
Does death need to make sense to your story and therefore your reader? Absolutely.
Part of being a writer is taking the things that don't make sense in this world and distilling them into something recogniziable and understandable for the reader. If a hero falls saving his friends, then that's a death the reader can understand. If a woman get hits by a car while chasing down her child, that's a death the reader can understand.
But if a man gets hit by lightning on page 3 and nobody seems to care because you didn't really focus on the death in your plot and theme, the theme of your book is now how cullous the world is. In other words, highly emotional moments, like a death, impact the story much more than other moments, and create shifts in tone, plot, and most importantly, theme.
In other words, anytime you write a death or other highly emotional moment into your story, make sure it's not there for shock value alone. Make it worth something.