Complex sentence: Amanda begins to notice Eli's strange mannerisms and when she tries to cut down his cornfield it begins to attack her, when she tries to escape she trips on a pole and her head is impaled on a broken pipe, killing her instantly.
Split into simpler sentences: Amanda begins to notice Eli's strange mannerisms and when she tries to cut down his cornfield it begins to attack her. She attempts to escape, but she trips on a pole and her head is impaled on a broken pipe, killing her instantly.