Here is the story I have been told:
Flight was DM to Loring, but over Vermont (I think 27,000'), without any warning, #3 didn't like one of its reduction gearbox gears and kicked it outboard to #4. That broke the blade on #4 and cause what you see. #3 prop assembly didn't like being on an airplane anymore and departed the A/C. It was found about a week later in VT or NH, where it actually cut down a 3-4 inch tree like a chain saw (former CC was given a Hercules chainsaw trophy of the tree). 23 minutes later we were safely on the ground at Pease where we conveniently shut down a SAC base & runway for 3-4 hours while the brakes cooled, until Grill could yank 'em off. Safety guys figured out, by listening to the cockpit voice recorder, that when this happened #3 oversped, tried to correct itself, then disintegrated. Took about a 1/2 sec for all this. If this happened the next day we would have been an hour or so from any terra ferma.
And yes, it is a Compass Call bird. Tail number 73-1592.