It's a pretty overused formula now, but always good for a great movie death:
Child is in imminent danger, hero saves child, but hero is suddenly killed in the process, child screams.
In this scene from Jaws 2, after the giant shark brings down a helicopter, everybody panics and little Sean falls into the water. Our hero Marge(Martha Swatek) quickly goes into the water and heaves him onto a floating hull, but the shark devours her before she can pull herself up.
Marge has joined the many characters throughout cinematic history know as the "Sacrificial Hero"
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