How do you kill a blind deaf person? You push them off a cliff, they would have no idea what just hit them!
Why would you make a joke like that about people who are blind and deaf?
I thought it was funny and I'm just trying to make you laugh.
People who are blind and deaf can still be productive members of our society. It's not right to imply that they be killed as if they are not worthy of existing. Read the story of Helen Keller and all that she achieved, I think you will find it very inspiring.