Complex sentence: They come across a tower where a walker is about to fall from the roof on top of Eugene, whom Abraham saves by shoving Eugene out of the way, but causes Tara to fall and injure her leg in the process.
Split into simpler sentences: They come across a tower where a walker is about to fall from the roof on top of Eugene. Abraham shoves Eugene out of the way, saving him, but causing Tara to fall and injure her leg in the process.