Sometimes it's just lack of good sense. The worst injury in recent times in New York occurred when a man smeared tuna fish on his hand and presented it to a large hungry male to lick off. The bear went CHOMP! and the unfortunate fellow lost some fingers. Even he realised how dumb he had been. All-in-all, the Eastern U.S. black bear has an outstanding safety record that I doubt is surpassed by any other comparably large animal, whether wild or domesticated.
In the more southern areas of the U.S., whether east or west, the situation is basically similar. California has never had a reported fatality or even a really serious injury from a black bear. The bears there, however, are a little more aggressive than the ones back East. For example, one unfortunate man in Northern California was bent over the front of his truck fixing it. A bear found the temptation irresitable, snuck up behind him, bit him in the butt, then ran off. In a couple of incidents in National Parks, two sleeping teenage boys were dragged out of their tents by bears in the night. This kind of incident has predatory overtones and deserves careful investigation. For the most part, the California black bear (the grizzlies which are the official state symbol have been long extinct) are pretty mellow and easy-going critters. The main problem associated with them is their enthusiastic and skillful theiving.
In more northerly areas, there have been a few serious incidents. Colorado has had 2 fatalities in the last 30 years; one involving a predatory black bear killing and partially devouring a sleeping camper, the other involving an angry bear breaking into a trailer after a man who had shot him. The older incident (near Durango) with the camper involved an old and starving male with badly worn teeth that was probably fairly desperate. I have heard that there have been 5 or 6 serious attacks in Washington State and 1 fatality since WWII, but I have not been able to find any details.
The most incidents have involved the Old Northwest area consisting of northern Minnesota, Wisconson and Upper Michigan. There seems to be a pattern here of perhaps one serious attack per decade and one fatality per generation. Some of these have involved successful or attempted predation on children. The most recent incident I have heard of was in the Boundary Waters area. It involved a grossly underweight (a little over 100 pounds) and probably crazed female that caught and seriously tried to eat two fishermen in separate incidents. Despite her puny size and weakened condition, she was easily able to overpower the substantially larger men. Their companions succeeded in fighting her off before she inflicted serious injury. She was shot when she attempted to terrorize a third encampment. She is the only U.S. bear I know of which was fully predacious; her man-eating drive was remarkably strong. She is also the only female predacious bear I have heard of.
