I guess he had been following school kids before the fatal time. I guess that bears must be attracted to bird seed. In my sister's case, the assumption was that there had been so much development in recent months that the bear's habitat had been disturbed, thus forcing it into city limits to find something to eat. In your case, you have a large forest right in your back yard and the bear probably thought that bird seed was just part of the menu. A large problem is that humans have a tendency to feed bears and make them completely unafraid of us.
Campers seem to be the most guilty parties.
The Pennsylvania Game commission has really started cracking down on campers who leave bait out for bears or who feed the bears on purpose. Hopefully that, and the relocation of the displaced bears will help keep them thriving in Pennsylvania. They are such powerful beasts and amazing to watch. Graceful they are NOT, though. It amazes me that they amble so clumsily along yet can cover great distances in little time if need be.