BFG All Terrain AT Failure

Driving down the highway I felt a wobble in the van.  Pulled over at the next rest area and found this bulge in the tire.

Top view shows the tread starting to separate where the bulge is.

Close up of where the tread might separate.  These tires are load range D.  Supposed to be enough for my heavy van.  I'll be buying new tires load range E now. 

If you have to change tires.  A shaded rest area is the place to do it.