As stupid as it sounds and since it happened on a curve. Take precautions and have a look to make sure the front part of the driveshaft is not turning with the transmission in drive.
It is very unlikely something further back than the transmission let go but never totally impossible. There have been cases of driveshaft welds letting go, Rear ends dropping out suddenly but very unusual on your model, or a cv joint disengaging with not too much fuss. Again highly unlikely just not to be overlooked.