How did The Undertaker get in a coma?

Answer 1

its a storyline used in 2010 the undertaker suffered an orbital bone injury the after a 619 from Rey Mysterio the storyline was that the undertaker was brutally attacked by his kayfabe half brother kane which put him in a coma or vegatative state kane would then go on to win the world heavyweight champion the undertaker would later return at summerslam to confront kane culminating in their feud reigniteing

Answer 2

it was actually Kane his brother who put him in a coma.

Answer 3

No. In his match against Rey Mysterio he broke a couple bones in his face. This whole coma thing is probably an excuse to heal. He should be back in a couple of weeks.