42" Rider Blew out the deck drive belt

[microsvc]

I was cleaning my deck through the hose port after a mow (smelled rubber much of the time I was mowing).
While I was cleaning the deck the blades stopped moving and the belt (less than 2 years old) blew out in pieces.
unsure why this happened. I ordered 2 spindles to install, but I dont know why this happened. Also noticed the right brake pad was worn through (left is OK).

What would cause this issue? See pics.

 

[StarTech]

You probably got a bearing failure in one of the spindles or idler pulleys.

The MTD 761-05007 is still available through one of my distributors and Cub Cadet. You need two 5/32 Stainless Steel Rivets to install it.