Garden Pests and Diseases: Giant oak w/ rot in the center, dead of course, 1 by Cearbhaill

Cearbhaill wrote:
I just had a 100+ foot red (I think) oak taken down as it did not bud out this year and was clearly dead. I just moved to this property last spring and do not recall if it was healthy then or not, but I had a good tree guy here several times and feel sure he would have noticed if it was dead then. He said he would have noticed, anyway.
He was not on site for the final thud- just the workers remained, so I can't ask him about this today and thought someone here might have an idea.

The center of the stump and the first round above it have rot in the middle- clear through a 16" round. The margins of the rot are moist and soft, but not terribly so- just a bit. It smells... oakey, not rotty or bad in any way.
If it would help I can blow out the sawdust after it cools down and take a closer and/or higher resolution photo.

I am zone 6b eastern Kentucky and this tree borders old growth woods full of other oaks and hickory... mostly. If it is at all possible to identify what happened so I can prevent it occurring again I would be grateful. I absolutely hate losing old trees, and hate having to pay for it, too, although we will be heating with this one in 2010.

And thoughts or instructions on how to get this figured out are appreciated.