I remember the scene in The Amazing Spider-Man 2 where Gwen falls from the clock tower and Spider-Man uses his web to catch her before she touches the ground, and he did catch her.
But I still don't understand what exactly she died from.
I'm at work so I can't upload images due to internal security, but if you freeze-frame the exact moment the web that caught her pulls taut, you can see she clearly hit the ground. Her head hits the ground and so do her hands.
So, while it's possible her neck snapped, it's also pretty clear that part of her body lands with a thud.
Try to freeze this video at the 51 second mark and you'll see it.