Transaxle cover blew up

My transaxle suddenly sounded metal grinding when I just started to drive first time in the morning, just within a block, trasxale cover blew up (I can see the drive belt and gears on the driver side near front tire), drained out all fluid. What caused it and how did this happen? There was no sign of leakage at all, just out of the blue blew up the transaxle!

The pin for the spider gears in the transaxle let go and blew a hole thru the cover.

They actually make a kit to prevent this from happening if you catch it in time.

Tester

And I thought a Caravan would be a boring vehicle! Good thing I got rid of the Rav4.

That pin takes on a heck of a lot of force during rapid accelerations and decelerations. Especially so if the wheels were making intermittent contact with the road surface so it got jerked back and forth between solid contact and slipping. It’s actually surprising to me it works at all. But somehow it does, most of the time anyway. There’s an informative thread where the experts here explained and answered questions about how differentials work, posted maybe 3 years ago. Try searching for it maybe.