By darkman61288 Comments
This what I read on DCcomics.com's Batman Bio:
What the world doesn’t know is that Bruce’s mother, Martha Wayne, was the real target for the mob hit the night that Bruce’s parents were murdered. While in the ambulance it was discovered that she was still alive, and the doctors were able to save her. She signed over guardianship of Bruce to the family butler, Alfred Pennyworth, in hopes that the young boy would be protected, and she was put into the Witness Protection Program and sent to Smallville, Kansas—a quiet town where nothing ever happens.
There Martha met and married a nice young man named Jonathan Kent. With a new inability to carry a child due to the bullet wound, Martha and Jonathan were unable to have the baby they so longed for. However, their prayers were answered when out of the sky, a rocket landed in a nearby field as the couple was driving by. There was a small baby in the rocket who they adopted and gave the name Clark Kent, and who would grow up to be Superman!
Now I hope it is a joke. It is also on the Superman Bio.