The oak trees in my yard are dying very quickly. Over the last 2 years about 10 trees have succumbed to this quick death. It appears to have been following a path, 1 after the other. Some are younger, some are old. The death happens within approximately 4 months. Some oak trees are not affected, like I said it definitely seems to be forming a path of dead trees.
There are alot of fruiting bodies from a species of fungus growing from the trunk. That's NEVER a good sign.
Trees can take many years to show signs of a decline in health, and death can come suddenly when the circumstances are right (or bad in the trees' case).