so my truck caught on fire

[Guilty-by-Design]

like every Wednesday at 4:00pm i was cruizing down 8th street on my way to work, when suddenly my truck seams to stall out. I come to a stop and i am promptly greeted by a huge plume of white smoke from under the hood that quickly becomes black smoke... at this point i throw it in park and slam the e-break on and yank the hood release. by the time i get around front the pop the hood an older gentleman meets me, fire extinguisher in hand. A few well aimed blasts and the fire is out. I thank the man for helping and he is gone just as fast as he had arrived. a quick under the hood inspection reviles a well done wire bundle against the passenger firewall and a melted hard plastic vac line or two. i thought to myself that would explain the black smoke but what about the white??? as it turns out im standing in what appears to be the better part a quart of tranny fluid... By this time the cops and fire department are there asking the normal question. The cop then informed me of the huge trail of tranny fluid i left, two car lengths worth.

My question to you is what would cause that much tranny fluid to leak into the engine compartment.

What i know:
-It was localized on the passenger side
-Transmission lines to the radiator are fine
-It was tranny fluid not oil
-Only apparent source is top of fill tube

any help would be greatly appreciated