Although without looking at a sample under a microscope, I can't entirely rule out a fungal disease, my impression is that some of the roots of your spruces are dying from too much water.   Soil high in clay content, as most soil in New Castle County is, drains slowly.   Alberta spruce, which prefers soil that drains quickly, cannot absorb water when the soil is saturated.  We have had two very wet springs in the last two years.  Ironically, the parts of the trees fed by roots in saturated soils, die from lack of water. Where the damage is small, you can prune out the dead branches, but where there is a lot of dieback, you really can't save the trees.