what did I tear up and how can I fix it?

my car mitsubishi diamante stop moving while in drive,then as I revved it up to go I heard a breaking of metal sound it almost sounded like glass hitting the ground under the car.When I pushed the car out the way,it appeared to be transmission fluid (lots of it)broken metal pieces,and cogswell cogs along with spacely sprockets on the ground.Please tell me exactly what I destroyed.thank you