I saw the same initial report a few hours ago.

 

Fortunately they proved wrong and it was only a fire while on the ground, and the crew is safe. I just hope the damage was not to extensive as we need all the air frames we can get.

The truth is in between. The aircraft apparently had an engine fire while taxiing, which reached the munitions bay and caused the bombs to cook off. Fortunately the crew was able to evacuate (presumably without testing the effectiveness of the "loud handle") and there were no casualties; unfortunately the airframe is a catastrophic loss and there's probably a big hole in the ramp for ECES to patch up.
...so the CENTAF is down one B-1 and some concrete, but thank Bob the flight crew made it out safely.