How did Emmett become a vampire?

Rosalie almost died when he drunk husband and his drunk friends beat her and left her to die in the road. all that human-Rosalie wanted was someone to adore her and a baby.

Rosalie was hunting one day, and saw Emmett getting mauled by a bear. she was in desperate need of a companion so she saved him and had carlisle change him for her.

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Because Rosalie saw him dieing and decided to save him in book 3 Eclipse