Bruce Wayne was a small boy when it happened.
When his parents were murdered by a criminal in 
Crime Alley.  He had told them not to go, but 
instead, they went through the alley to their deaths.
The most tragic about the whole incident was that
he witnessed the entire thing.

After his death, he was alone with Alfred, the
butler.  He began training himself and working himself
to no end, building himself up.  Eventually, he got
himself in great physical shape, and expanded his 
mind to new and different ideas.

It was one day that he decided to try out his crime
fighting.  But he needed a secret identity to keep
criminals and even police from knowing his true
identity.  As he thought about it, he saw a bat in
the window of Wayne Manor, and decided that that was
what he would become.  An animal of the night.  He
then began his quest for vengance from criminals.  He
still continues to fight, and will always seek vengance
from his parents' death.