carrier bearing bracket

[Broken_down?]

got a chvy 68 lb with 350 eng. Night before last I heard a draggin noise or so thats what I thought. I pulled over and found the center carrier bearing bracket broke clean in 2. It snaped right @ the part where the bracket starts to go around the bearing so the entire round part of the bracket was left around the bearings. But it was spining and making noise. So we cut off the broken round part and got some chain and stabilized it best I could. made it home.. But what can cause this to happen? There is almost no pressure on that bracket other then the drive shaft right?

Rich