How did emit become a vampire in twilight?

Answer 1

He was attacked by a bear while hiking and Rosalie found him. He reminded her of her friend's* son (because of his curly hair) so she carried him back to Carlisle who turned him into a vampire. It says so in Eclipse. * Her friends name was Vera

Answer 2

Emmet Cullen became a vampire when he was being attacked by a bear, Rosalie found him and he reminded her of a little baby her friend, so she went back to Carlisle and he bit him, because she didn't have the will power.

Answer 3

Emmett was being attacked by a bear, when Rose found him. She got rid of the bear (doesn't particuarly specify), and carried him hundreds of miles back to Carlisle, and asked him to change Emmett. He did. Rose asked him to do this because Emmett had dimples just like Vera's (Rose's friend when she was human,) son.