First let me say that this is in regards to my wife's Kia Spectra. As you may or may not know there are no forums worth a crap for Kia. I have a Camaro so let's pretend this happened to it.
We were driving and suddenly the car slows down and accelerating does nothing but rev the engine. No gear works but park and there is no engagement action when shifting to any gear. There is a slight whirring noise now but there was absolutely no noise that indicated something broke when it happened. What could this be? It is an auto tranny. Thanks so much.

 

maybe the torque converter came apart.. could have also broke the ears off the torque converter.. I had that happen once.... destroyed the tranny... but never felt or heard a thing.